JP2001168449A - Optical transceiver module - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Since an electric signal wraps around from an optical transmitting means to an optical receiving means, a transmitting electric signal completely unrelated to the receiving electric signal is superimposed on the receiving electric signal, as if noise increased. As a result, there is a problem that the receiving characteristics are significantly deteriorated. SOLUTION: A light receiving element, one of which has the same potential as a constant potential portion,
The other comprises an output section having a different potential from the constant potential section,
Light receiving means having output means for outputting an electric signal converted by the light receiving element to the outside; light emitting element; and input means for inputting an electric signal to the light emitting element, comprising an input part having a potential different from the constant potential part. An optical waveguide provided at least between the optical receiving means and the optical transmitting means, an optical signal transmitted by the optical transmitting means, and a light to be received by the optical receiving means. Optical multiplexing / demultiplexing means for selecting a signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmitting / receiving module used in an optical communication system, and more particularly to an optical transmitting / receiving module in which crosstalk between transmission and reception is reduced and cost is reduced.

[0002]

2. Description of the Related Art With the spread of optical communication networks such as optical fibers, there is an increasing demand for cost reduction of optical transmitting and receiving modules used in optical communication networks. As such an optical transmitting and receiving module with a low cost, a light emitting element and a light receiving element are integrated on the same substrate to reduce the number of components and realize miniaturization. However, when the light emitting element and the light receiving element exist on the same substrate, there is a problem that signal interference between transmission and reception (light and electrical crosstalk) occurs because the light emitting element and the light receiving element approach each other. In order to suppress such signal interference between transmission and reception, there is a type in which a filter is inserted in an optical waveguide between a light emitting element and a light receiving element.

[0003] To explain a specific structure, a light emitting element and a light receiving element are arranged to face each other, and an optical filter is inserted between them. This optical filter transmits the input light and guides it to the light receiving element, reflects the output light, and guides the output light to the input / output common waveguide. With such a structure, the outgoing light that is not guided to the waveguide does not leak to the light receiving element side, and the light is reflected by the filter and the waveguide is folded so that the light emitting element and the light receiving element can be connected even in a small substrate. The distance can be increased, and suppression of interference between transmission and reception signals is achieved.

FIG. 7 is an illustration of the Institute of Electronics, Information and Communication Engineers Electronics Society Conference C-3-1 in 1998 by Hashimoto et al.
FIG. 11 is a perspective view showing the above-described conventional optical transceiver module disclosed in FIG. In the figure, reference numeral 100 denotes a platform substrate formed of silicon or the like, and 101 denotes a light emitting element (laser / laser) for transmitting an optical signal in a 1.3 μm band.
A diode 102 has a wavelength of 1.
It is a light receiving element (photodiode, hereinafter referred to as PD) for receiving an optical signal in the 5 μm band. Reference numeral 103 denotes an optical waveguide constituting a Y-shaped planar waveguide, and reference numeral 104 denotes an optical waveguide 1.
An optical filter such as a multi-layer film filter is provided with a slit at the intersection of 03, which reflects an optical signal in the 1.3 μm band and transmits an optical signal in the 1.5 μm band.

[0005] 105 is a monitor PD, 106 is a PD 102
And a preamplifier IC 107 for amplifying the electric signal received by the PD 102. The preamplifier IC 107 is a reception signal output lead for outputting the received electric signal. And a lead having a potential different from the potential. Reference numeral 108 denotes a transmission signal input lead for inputting an electric signal to be transmitted to the LD 101, and includes a lead having the same potential as the grounded lead frame 109 and a lead having a potential different from the potential of the lead frame 109. 109 is a lead frame, 1
Reference numeral 10 denotes an input / output port through which a received optical signal and a transmitted optical signal enter and exit. A wire 111 electrically connects the PD 102 and the LD 101 to the reception signal output lead 107 and the transmission signal input lead 108, respectively.

Next, the operation will be described. A transmission electric signal is input from the transmission signal input lead 108 to the LD 101 via the wire 111. The transmission electric signal input to the LD 101 is converted into an optical signal in the 1.3 μm band and is incident on the optical waveguide 103. 1.3 through optical waveguide 103
The optical signal in the μm band is reflected by the optical filter 104 disposed at the intersection of the optical waveguide 103, propagates through the other optical waveguide 103 of the Y branch, and becomes a transmission optical signal as an input / output port 1.
It is output from 10. Further, the LD 101 uses the light output from the front surface as an optical signal, but also outputs some light from the back surface. The monitor PD 105 is an LD 101
And an output monitor for performing feedback control so that the optical output does not become unstable due to the temperature characteristics of the LD 101 or the like.

Further, the optical waveguide 103 is connected from the entrance / exit port 110.
When a received optical signal in the 1.5 μm band is input to the optical waveguide 103, the optical signal propagates through the optical waveguide 103, passes through the optical filter 104 without being reflected even when reaching the intersection of the optical waveguide 103, and is input to the PD 102. The PD 102 converts the input received optical signal into a received electric signal. This received electric signal is a preamplifier IC
The signal is amplified by 106 and output to an external device (not shown) from a reception signal input lead 107 via a wire 111.

As described above, the optical transceiver module shown in FIG. 7 is an optical waveguide 103 between the LD 101 and the PD 102.
Although the optical filter 104 is provided in the optical disk 10 to suppress signal interference between transmission and reception, in practice, the LD 10
An electric signal wraps around from the optical transmission unit including the transmission signal input lead 1 and the transmission signal input lead 108 to the optical reception unit including the PD 102, the preamplifier IC 106, and the reception signal input lead 107.

For this reason, the inventor of the present application has searched for the cause of the sneak of the electric signal from the optical transmitting means to the optical receiving means, and found the electric signal from the optical transmitting means to the optical receiving means through a route shown in FIG. Clarified that the wraparound occurs.

FIG. 8 is an explanatory diagram for explaining interference of electric signals between transmitting and receiving elements in the optical transmitting and receiving module shown in FIG. In FIG. 8, the symbol “●” in “○” and the symbol “×” in “○” indicate the amplitude direction of the electric field of the electric signal leaked into the space, which is perpendicular to the plane of the paper, and indicates the direction in front of the paper and the opposite direction. Reference numerals 112a and 112b denote electrodes of the light transmitting means and the light receiving means, respectively. Note that the same components as those in FIG. 7 are denoted by the same reference numerals, and redundant description will be omitted.

First, a transmission signal input lead 108 for inputting an electric signal to the optical transmission means and a reception signal output lead 107 for outputting an electric signal from the light receiving means share a lead frame 109. An electric signal wraps around from the light transmitting means to the light receiving means via the lead frame 109. This is the route in FIG. Also, at this time, even if the potential is floated in a DC manner using a capacitor or the like, an electric signal is sneak in the case of being grounded at a high frequency.

The sneaking of electric signals in this path is caused by the inability to create an ideal ground potential which is always a constant potential. In an optical transmitting and receiving module including an optical receiving unit for detecting a signal, even a slight change in the ground potential affects the receiving characteristics.

As another path, the electric signal input to the optical transmitting means is radiated into the space, and the electric signal propagated through the space is combined with the optical receiving means and goes around. This is the route in FIG. The transmission electric signal leaked into the space such as this route to the optical receiving means is caused by the leakage of the transmitted electric signal by the electrodes 112b, 112b and the wire 1 in the optical receiving means.
11, generated by electromagnetic induction caused by passing through a closed circuit composed of optical devices such as the PD 102 and the preamplifier IC 106, and the leads 108 and the like.
At this time, the amplitude direction of the electric field of the leaked transmission electric signal is determined by the two electrodes (the electrode 112a on which the LD 101 is formed and the electrode 112a connected to the lead frame 108 via the wire 111) 112a, 112a of the optical transmission means through which the transmission electric signal flows.
Are formed on the platform substrate 100, and both electrodes 1
So that 12a and 112a are connected (parallel to the substrate 100)
Since the electric field is oscillating, the direction is substantially parallel to the substrate 100. For this reason, in the conventional optical transceiver module, it was necessary to ground one electrode 112b of the optical receiving means in order to reduce the cross-sectional area of the closed circuit.

[0014]

Since the conventional optical transmitting / receiving module is configured as described above, an electric signal wraps around from the optical transmitting means to the optical receiving means.
There has been a problem that a transmission electric signal having no relation to the reception electric signal is superimposed on the reception electric signal, as if the noise increased, and the reception characteristics deteriorated significantly.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to reduce the interference of electric signals between transmission and reception and to obtain a low-cost optical transmission and reception module.

[0016]

An optical transmitting and receiving module according to the present invention is provided on a substrate and has a light receiving element for converting a received optical signal into an electric signal, one of which has the same potential as a constant potential portion, and the other has a constant potential. A light receiving unit comprising an output unit having a potential different from the potential unit and having an output unit for outputting an electric signal converted by the light receiving element to the outside; and an optical signal provided on the same substrate as the light receiving element. A light transmitting element having an input section having a potential different from that of the constant potential section, and having an input section for inputting an electric signal to the light emitting element; and at least a light receiving section and an optical transmitting section. An optical waveguide that is provided so as to be interposed therebetween and through which an optical signal propagates; an optical signal that is provided in the optical waveguide and that is transmitted by the optical transmitting unit from the optical signal that propagates through the optical waveguide; and an optical signal that is to be received by the optical receiving unit Hikaru to sort out It is intended and means.

An optical transmitting / receiving module according to the present invention is provided between an optical receiving unit and an optical transmitting unit in parallel with a substrate,
A conductive shielding plate having the same potential as the constant potential portion is provided.

An optical transmitting / receiving module according to the present invention is provided on a substrate, and a light receiving element for converting a received optical signal into an electric signal, one of which has the same potential as the constant potential portion and the other has a potential different from the constant potential portion. A light receiving unit having an output unit having an output unit for outputting an electric signal converted by the light receiving element to the outside, and a light emitting element provided on a different substrate from the light receiving element and converting the electric signal into an optical signal. An optical transmission unit having an input unit having a potential different from that of the constant potential unit and having an input unit for inputting an electric signal to the light emitting element, and interposed at least between the optical reception unit and the optical transmission unit. An optical waveguide that is provided and propagates an optical signal; and an optical waveguide that is provided in the optical waveguide and selects an optical signal transmitted by an optical transmitting unit from an optical signal transmitted through the optical waveguide and an optical signal to be received by the optical receiving unit. With demultiplexing means It is obtain things.

An optical transceiver module according to the present invention includes a conductive film formed on the upper surface of a substrate and / or an upper surface of an optical waveguide, and connection means for electrically connecting the conductive film and the constant potential portion. .

In the optical transmitting / receiving module according to the present invention, the connecting means is disposed between the optical receiving means and the optical transmitting means so as to shield the input means.

An optical transceiver module according to the present invention uses a conductive film formed on an upper surface of a substrate as a connection pattern for connecting an optical waveguide to the substrate.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a perspective view showing an optical transceiver module according to Embodiment 1 of the present invention. In the figure, 1
Is a platform substrate (substrate) formed of silicon or the like, and 2 is an L for transmitting an optical signal in a 1.3 μm band.
D (light emitting element, light transmitting means) and 3 is a PD (light receiving element, light receiving means) for receiving an optical signal in a wavelength band of 1.5 μm. Reference numeral 4 denotes an optical waveguide constituting a Y-type planar waveguide, which is referred to as an optical waveguide including not only a light path but also a substrate on which the optical waveguide is formed. In the following embodiments, an optical waveguide is defined similarly. A multilayer film 5 is provided with a slit (optical multiplexing / demultiplexing means) at the intersection of the optical waveguide 4 to reflect a transmission optical signal in a 1.3 μm band and transmit a reception optical signal in a 1.5 μm band. An optical filter (optical multiplexing / demultiplexing means) such as a filter.

6 is a monitor PD (optical transmission means), 7 is a PD
3, a preamplifier IC (light receiving means) for amplifying the electric signal received by the PD 3, and 8 a reception signal output lead (output unit, output means,
In the light receiving means), the lead (output part) of the lead frame 10 grounded to the constant potential part (ground) and the lead of the lead frame 10 have no electrical connection and are different from the potential of the lead frame 10. And a lead (output unit) of a potential (potential different from ground). Reference numeral 9 denotes a transmission signal input lead (input unit, input means, optical transmission means) for inputting an electric signal to be transmitted to the LD 2, and a lead frame 10
Has no electrical connection with the lead of lead frame 1
It is composed of two leads (input units) having a potential different from 0.

Reference numeral 10 denotes a lead frame (constant potential section) on which all the components of the optical transceiver module are provided. 11a is a wire (output part, output means,
Optical receiving means), 11b has one end connected to a transmission signal input lead 9,
9. Wires (input unit, input unit, optical transmission unit) electrically connected at the other end to an anode electrode (input unit) and a cathode electrode (input unit) (not shown) of the LD 2 in the optical transmission unit. . Also, the transmission signal input lead 9,
9, the wires 11b, 11b, and the not-shown anode electrode and cathode electrode of the LD 2 constitute an input means of the light transmitting means. Reference numeral 12 denotes a driver IC that supplies a transmission electric signal to the optical transmission unit via the transmission signal input lead 9 and the wire 11b. A is an input / output port (optical waveguide) through which a received optical signal and a transmitted optical signal enter and exit.

Next, the operation will be described. Driver IC
The transmission electric signal is supplied to the optical transmission means including the LD 2 and the monitor PD 6 via the transmission signal input lead 9 and the wire 11 b by the transmission signal input 12. Transmission signal input lead 9,
9 and the wires 11b, 11b have no electrical connection with the lead frame 10 and have a potential different from the potential of the lead frame 10. Further, an anode electrode and a cathode electrode (not shown) of the LD 2 connected thereto have a potential different from the potential of the lead frame 10. Note that the above L
The anode electrode and the cathode electrode (not shown) of D2 are not only separated in potential from the lead frame 10 but also separated in high frequency. When the transmission electric signal is input, the LD 2 converts the transmission electric signal to a wavelength of 1.3 μm.
The optical signal is converted into a band optical signal and output to the optical waveguide 4. At this time, the monitor PD6 disposed on the rear surface of the LD2 monitors the light output from the rear surface of the LD2 in order to perform feedback control so that the output does not become unstable due to the temperature characteristics of the LD2.

The transmission optical signal output from the optical transmission means propagates through the optical waveguide 4, and the 1.3 μm band transmission optical signal is reflected at the intersection of the optical waveguide 4 where the optical filter 5 is provided, and the Y-branch is transmitted. The light enters the other optical waveguide 4 and is output from the input / output port A as a transmission optical signal.

On the other hand, the wavelength 1.
The received optical signal in the 5 μm band propagates through the optical waveguide 4 and reaches an intersection of the optical waveguide 4 where the optical filter 5 is provided. At this time, the received optical signal passes through the optical filter 5 and
Is input to The PD 3 converts the received optical signal into a received electrical signal. The converted received electric signal is amplified by the preamplifier IC 7 and output to an external device or the like via the wire 11a and the received signal output lead 8.

Next, features of the optical transceiver module according to Embodiment 1 will be described. As described above, the optical receiving means outputs a received electric signal via the received signal output lead 8. At this time, one of the leads constituting the reception signal output lead 8 is grounded to the constant potential portion (ground).
A part of the closed circuit of the light receiving means constituted by the two electrodes of the PD 3, the wire 11a, the optical device such as the PD 3 and the preamplifier IC 7, and the lead 8, etc. is opened, and its cross-sectional area is reduced. As a result, as in the path in FIG. 8, the transmission of the transmission electric signal to the optical receiving means caused by the electromagnetic induction caused by the electric signal propagating in the space passing through the closed circuit is suppressed.

Further, in addition to the output means of the optical receiving means, such as a reception signal output lead 8 having one side grounded to a constant potential section (ground) and the other having a potential different from that of the constant potential section, this embodiment is also applicable. 1, the transmission signal input lead 9,
9, the input means of the light transmitting means including the wires 11b, 11b and the anode electrode and the cathode electrode (not shown) of the LD 2 have a potential different from the potential of the lead frame 10. Note that the anode electrode and the cathode electrode (not shown) of the LD 2 are not only separated in potential from the lead frame 10 but also separated in high frequency. Thus, it is possible to prevent an electric signal from flowing from the optical transmitting unit to the optical receiving unit via the lead frame 10 which is a common ground.

As described above, according to the first embodiment, the PD 3 provided on the platform substrate 1 for converting a received optical signal into an electric signal and the lead frame 10 having one of the constant potential portions are the same. A light receiving device comprising a wire 11a having the other potential different from that of the lead frame 10, a reception signal output lead 8, and a cathode and an anode electrode of the LD2, and an output means for outputting an electric signal converted by the PD3 to the outside; Means, an LD 2 provided on the same substrate 1 as the PD 3 for converting an electric signal into an optical signal, a transmission signal input lead 9 having a potential different from that of the lead frame 10, and a wire 11b, and an electric signal is input to the LD 2 An optical transmission unit having an input unit and at least an optical transmission unit provided between the optical reception unit and the optical transmission unit for transmitting an optical signal An optical multiplexing / demultiplexing means provided in the optical waveguide 4 for selecting an optical signal transmitted by the optical transmitting means from an optical signal propagating through the optical waveguide 4 and an optical signal to be received by the optical receiving means. The provision of the optical filter 5 makes it possible to reduce the cross-sectional area of the closed circuit formed by the components of the optical receiving means, thereby preventing the electric signal leaked into the space from flowing to the optical receiving means. In addition, it is possible to prevent the electric signal from the optical transmission unit from going around the optical reception unit via the lead frame 10. As a result, it is possible to provide an optical transmitting and receiving module having characteristics that there is no sneaking of electric signals, there is little interference of electric signals between transmission and reception (low crosstalk), and deterioration of reception sensitivity is small.

Embodiment 2 In the first embodiment, the input unit electrically connected to the constant potential unit and the output unit not electrically connected to the constant potential unit are provided in order to suppress the wraparound of the electric signal between transmission and reception. Although an example has been described, in the second embodiment, in addition to the configuration of the first embodiment, a conductive shielding plate for shielding an electric signal propagating in a space is provided between transmission and reception.

FIG. 2 is a perspective view showing an optical transceiver module according to Embodiment 2 of the present invention. In the figure, 13
Is a metal shielding plate (conductive shielding plate) electrically connected to a constant potential portion (ground). The same components as those in FIG. 1 are denoted by the same reference numerals, and duplicate description will be omitted. FIG. 2 shows a configuration in which a metal shielding plate 13 is added to the configuration of the first embodiment.
7, wires 11a and 11b, and reception signal output lead 8
And the transmission signal input lead 9 are not shown.

Next, the operation will be described. Embodiment 2
The operation of the optical transceiver module according to the first embodiment
Is the same as that shown in the above, so duplicate explanations are omitted,
Here, the outline of the metal shielding plate 13 will be described. As shown in FIG. 8, the optical transmitting means is formed on the substrate 1,
Both the anode and cathode electrodes of the LD 2 in this light transmitting means are also arranged in parallel on the substrate 1. Since an electric signal of much higher power is supplied to both of these electrodes as compared with the PD 3, an electric field vibrating in parallel with the substrate 1 is generated so as to connect between the two electrodes. That is, a leaked transmission electric signal leaking into the space is generated from the transmission electric signal applied to both electrodes. The leaked transmission electric signal whose electric field oscillates in parallel with the substrate 1 is
Electric signals are wrapped around by the electromagnetic induction generated by propagating in the space, reaching the light receiving means, and passing through a closed circuit formed by the components of the light receiving means.

Therefore, in the second embodiment, as shown in FIG. 2, a metal shield plate 13 electrically connected to the lead frame 10 and grounded to the ground is provided between the light transmitting means and the light receiving means. By arranging in parallel with 1, the leaked transmission electric signal is absorbed by the metal shielding plate 13 before reaching the optical receiving means.

The metal shield plate 13 does not necessarily need to be provided so as to cover the light transmitting means and the light receiving means.
It is possible to sufficiently absorb the leaked transmission electric signal simply by passing the light transmission means or the light reception means in parallel with the uppermost surface of the substrate 1 on which the light transmission means or the light reception means is mounted.

As described above, according to the second embodiment, the lead frame 1 which is provided between the optical receiving means and the optical transmitting means in parallel with the substrate 1 and is a constant potential portion (ground).
Since the metal shielding plate 13 having the same potential as 0 is provided, it is possible to shield the electric signal from the optical transmitting means side leaked into the space and to prevent the electric signal from sneaking into the optical receiving means. Accordingly, it is possible to provide an optical transmitting and receiving module having a characteristic of low interference (low crosstalk) of electric signals between transmission and reception, and having little deterioration in reception sensitivity.

Embodiment 3 In the second embodiment, the example in which the conductive shielding plate for shielding the electric signal leaking into the space is provided. However, in the third embodiment, the conductive film for shielding the electric signal leaking into the space is provided on the optical waveguide. It is provided.

FIG. 3 is a perspective view showing an optical transceiver module according to Embodiment 3 of the present invention. In the figure, 11
c is a wire (connection means) for electrically connecting the metal film 14 and the lead frame 10 which is a constant potential portion (ground),
Reference numeral 14 denotes a metal film (conductive film) formed on the upper surface of the optical waveguide 4. The same components as those in FIG. 1 are denoted by the same reference numerals, and duplicate description will be omitted. FIG. 3 shows a configuration in which the metal film 14 is added to the configuration of the first embodiment. For simplicity, the preamplifier IC 7, the wires 11a and 11b, and the reception signal output lead 8 and the transmission signal input lead 9 are shown. Is omitted.

Next, the operation will be described. Embodiment 3
The operation of the optical transceiver module according to the first embodiment
Is the same as that shown in the above, so duplicate explanations are omitted,
Here, the outline of the metal film 14 will be described. The optical transmitting / receiving module of the present invention produces a large number of modules collectively from one wafer as in a normal semiconductor manufacturing process. At the time of manufacturing this module, the metal film 14 is formed collectively from the wafer by a metal thin film forming method such as plating or vacuum deposition without dividing the wafer into modules. As described above, in the second embodiment, the metal shielding plate 13 must be arranged for each module.
In the third embodiment, since the metal film 14 can be formed at the wafer level as described above, the manufacturing can be remarkably facilitated, and the cost involved can be reduced. Also, automated wire bonding apparatuses for connecting the wire 11c to the metal film 14 and the lead frame 10 and those capable of bonding without dividing a module from a wafer are widely used. This can further facilitate manufacturing.

The function of the metal film 14 is to absorb the leaked transmission electric signal propagating through the space, similarly to the metal shield plate 13 of the second embodiment. Thereby, it is possible to suppress the sneak of electric signals between transmission and reception.

FIG. 4 is a perspective view showing a modification of the optical transceiver module according to Embodiment 3 of the present invention. In the figure, reference numeral 10a denotes a lead (constant potential portion) of the lead frame 10 electrically connected to the wire (connection means) 11c.
The same components as those in FIG. 1 are denoted by the same reference numerals, and duplicate description will be omitted. 4 omits illustration of the preamplifier IC 7, the wire 11a, and the reception signal output lead 8 in FIG. 1 for simplicity of description.

Next, the operation will be described. The operation of the optical transceiver module according to the modification of the third embodiment is the same as that described in the first embodiment, and thus the duplicated description will be omitted. Here, the outline of the modification in the third embodiment will be described. explain. In a modification of the third embodiment, the metal film 14 is shielded so as to shield an electric signal leaking into space from wires 11b, 11b (input unit, input unit) connecting the optical transmission unit and the transmission signal input lead 9. And a wire 11 connecting the lead frame 10 as a constant potential part
, 11c are arranged between the optical transmitting means and the optical receiving means.

To explain a specific example, in the example of FIG. 4, the wires 11b, 11b protrude in the normal direction of the side surface of the substrate 1 in order to connect to the transmission signal input lead 9. Therefore, like the wires 11b, 11b, the lead frame 10
, 10a have wires 11c,.
, 11c are connected and projected in the normal direction of the side surface of the substrate 1 so that the wires 11b, 11b are hidden from the light receiving means side by the wires 11c,. By doing so, the electric signals leaking into the space from the wires 11b, 11b are absorbed by the wires 11c,..., 11c, and the electric signals do not flow to the optical receiving means.

In the above description, the wires 11c,.
, 10a of the lead frame 10 are shielded by connecting them to the leads 10a,..., 10a of the lead frame 10 so as to project in the normal direction of the side surface of the substrate 1. .., 11c may be used with a larger diameter, or one with a three-dimensional shielding effect obtained by changing the shape.

In the third embodiment, the example in which the metal film 14 is formed on the upper surface of the optical waveguide 4 has been described.
5 and 6, which are formed to be narrower than the substrate 1 and the upper surface of the substrate 1 is exposed, a metal film 1
By forming 4, the same effect as described above can be obtained.

As described above, according to the third embodiment, the metal film 14 formed on the upper surface of the substrate 1 and / or the upper surface of the optical waveguide 4 is electrically connected to the metal film 14 and the lead frame 10 which is a constant potential portion. Connecting wires 11c,.
, 11c, etc., it is possible to shield the electric signal from the optical transmitting means leaked into the space similarly to the second embodiment and to prevent the electric signal from wrapping around. It is possible to provide an optical transmitting and receiving module that has a characteristic of low signal interference (low crosstalk) and low deterioration of reception sensitivity. Further, since the metal film 14 can be formed at the wafer level, the shielding structure can be easily manufactured, and the manufacturing cost can be reduced. Further, the connection between the metal film 14 and the constant potential portion is established by using a wire that has been established in a manufacturing apparatus that can be automated, thereby further facilitating the manufacturing.

According to the third embodiment, the wires 11c, which are connection means, are connected between the light receiving means and the light transmitting means so as to shield the wires 11b constituting the input means of the light transmitting means. , ..., 11c are arranged,
It is possible to prevent the electric signal leaking from the wires 11b, 11b into the space from flowing to the optical receiving means.

Embodiment 4 In the third embodiment, an example in which a conductive film is provided on the upper surface of the optical waveguide to shield electric signals leaked into the space has been described. However, in the fourth embodiment, a conductive film is formed on the upper surface of the substrate and this conductive film is formed. The conductive film also functions as a connection pattern for connecting the optical waveguide and the substrate.

FIG. 5 is a perspective view showing an optical transceiver module according to Embodiment 4 of the present invention. In the figure, 4A
Is a V-shaped optical waveguide (optical waveguide) narrower than the substrate 1 made of a substrate different from the substrate 1, and uses, for example, silicon or the like as a material. 5a is provided on the end face of the optical waveguide 4A, and a slit (optical multiplexing / demultiplexing means) is provided at the intersection of the optical waveguide 4A.
And an optical filter (optical multiplexing / demultiplexing means) such as a multilayer filter that reflects an optical signal in a wavelength band of 1.3 μm through this slit and transmits an optical signal in a wavelength band of 1.5 μm. 14
a is a metal film (conductive film, connection pattern) formed on the upper surface of the substrate 1, and B is an optical fiber (optical waveguide) for exchanging optical signals with the optical waveguide 4A. The same components as those in FIG. 1 are denoted by the same reference numerals, and duplicate description will be omitted.
5 omits illustration of the preamplifier IC 7, the wires 11a and 11b, the reception signal output lead 8 and the transmission signal input lead 9 in FIG.

Next, the operation will be described. The anode electrode and the cathode electrode (not shown) of the LD 2 are not only separated in potential from the lead frame 10 but also separated in high frequency. When the transmission electric signal is input, the LD 2 converts the transmission electric signal into a transmission optical signal having a wavelength band of 1.3 μm and outputs it to the optical waveguide 4A. The monitor PD6 disposed on the back of the LD2 monitors the light output from the back of the LD2 in order to perform feedback control so that the output does not become unstable due to the temperature characteristics of the LD2. The operation up to this point is the same as in the first embodiment.

The transmission optical signal output from the optical transmission means propagates through the optical waveguide 4A, and the 1.3 μm transmission optical signal is reflected at the intersection of the optical filters 5a provided on the end face of the optical waveguide 4A. Guided to the V-branched optical waveguide 4A,
It is output as a transmission optical signal via the optical fiber B.

On the other hand, the received optical signal in the 1.5 μm band input via the optical fiber B propagates through the optical waveguide 4A and reaches the intersection of the optical filter 5a. At this time, the received optical signal passes through the optical filter 5a and is input to the PD 3. The PD 3 converts the received optical signal into a received electrical signal. The converted received electric signal is amplified by the preamplifier IC 7 and output to an external device or the like via the wire 11a and the received signal output lead 8.

Next, the features of the optical transceiver module according to the fourth embodiment will be described. Metal film 14a formed on substrate 1
Is used as a connection pattern for connecting the optical waveguide 4A to the upper surface of the substrate 1. This eliminates the need for a special structure for shielding the electric signal leaked into the space, and the formation can be performed at the wafer level as in the third embodiment. Means such as solder is used to connect the optical waveguide 4A and the substrate 1 via the metal film 14a as a connection pattern. This is because devices that automatically perform connection using molten metal such as soldering have been established, and the use of these devices can facilitate the manufacture of the shielding structure. Further, since the optical waveguide 4A is formed narrower than the substrate 1, when the optical waveguide 4A is connected to the substrate 1 as shown in FIG.
4a is exposed. The electrical connection between the metal film 14a and the lead frame 10 is made at the exposed portion of the metal film 14a. Further, the connection between the metal film 14a and the constant potential portion is established by using a wire for which a manufacturing apparatus that can be automated is established as in the third embodiment, thereby facilitating the manufacturing.

The function of the metal film 14a is to absorb the leaked transmission electric signal propagating in the space, similarly to the metal shield plate 13 of the second embodiment. Thereby, it is possible to suppress the sneak of electric signals between transmission and reception.

As described above, according to the fourth embodiment, since the metal film 14a formed on the upper surface of the substrate 1 is used as a connection pattern for connecting the optical waveguide 4A to the substrate 1, the optical waveguide 4A Film for shielding electric signals leaked into space by connecting patterns for connecting
The optical transmission / reception has a characteristic that there is little interference of electric signals between transmission and reception (low crosstalk) and that there is little deterioration in reception sensitivity by using the same as a. Modules can be provided at low cost.

The fourth embodiment can be applied to the configurations in all the above-described embodiments, and the same effects as above can be obtained.

Embodiment 5 In the above embodiment, the LD and the PD are formed on the same substrate, but in the fifth embodiment, the LD and the PD are formed on different substrates.

FIG. 6 is a perspective view showing an optical transceiver module according to Embodiment 5 of the present invention. In the figure, 3a
Is a PD (light receiving element) formed from a substrate different from the substrate 1 provided with the optical transmitting means, and 3b is a PD carrier (optical receiving means) on which the PD 3a is mounted, and is formed from the same substrate as the PD 3a. The same components as those in FIG. 5 are denoted by the same reference numerals, and redundant description will be omitted. FIG. 6 shows the preamplifier IC 7 and the wire 1 shown in FIG.
The illustration of the reception signal output leads 8 and the transmission signal input leads 9 is omitted.

Next, the operation will be described. Embodiment 5
The operation of the optical transceiver module according to the fourth embodiment
Is the same as that shown in the above, so duplicate explanations are omitted,
Here, an outline of the optical transceiver module according to the fourth embodiment will be described. Since the electric signal applied to the LD 2 has a high power, an electric signal which propagates through the substrate to the optical receiving means is generated. Therefore, Embodiment 5
By using separate substrates for the substrate on which the light transmitting means is formed and the substrate on which the light receiving means is formed, it is possible to prevent electric signals from the light transmitting means from flowing around the light receiving means via the substrate.

As in the first embodiment, one of the leads constituting the reception signal output lead 8 is grounded to a constant potential portion (ground), so that the two electrodes of the PD 3 and the wire 11a, a part of a closed circuit of an optical receiving means composed of an optical device such as the PD 3a and the preamplifier IC 7, and a lead 8 is opened to reduce the cross-sectional area thereof. As a result, as in the path in FIG. 8, the transmission of the transmission electric signal to the optical receiving means caused by the electromagnetic induction caused by the electric signal propagating in the space passing through the closed circuit is suppressed.

Further, in addition to the output means of the light receiving means, which includes a reception signal output lead 8 having one potential grounded to a constant potential portion (ground) and the other having a potential different from that of the constant potential portion, this embodiment is also applicable. 5, the transmission signal input lead 9, wires 11b, 11b, and L
Input means D2 including an anode electrode and a cathode electrode (not shown) has a potential different from the potential of the lead frame 10. Note that the anode electrode and the cathode electrode (not shown) of the LD 2 are not only separated in potential from the lead frame 10 but also separated in high frequency. Thus, it is possible to prevent an electric signal from flowing from the optical transmitting unit to the optical receiving unit via the lead frame 10 which is a common ground.

In the above description, an example is shown in which the light transmitting means is provided on the substrate 1 on which the optical waveguide 4A is provided. However, the same effect can be obtained by providing the optical waveguide 4A on the substrate on which the light receiving means is formed. Play.

As described above, according to the fifth embodiment, the PD 3a provided on the substrate and converting a received optical signal into an electric signal, and one of which has the same potential as the lead frame 10 which is a constant potential portion, An optical receiving means, comprising: a wire 11a having a potential different from that of the lead frame 10; a reception signal output lead 8; a cathode and an anode electrode of the LD2; and output means for outputting an electric signal converted by the PD3 to the outside. , An LD 2 provided on a substrate 1 different from the PD 3 a to convert an electric signal into an optical signal;
An optical transmission means comprising a transmission signal input lead 9 having a potential different from 0 and a wire 11b and having an input means for inputting an electric signal to the LD 2, and interposed at least between the optical reception means and the optical transmission means. The optical waveguide 4A provided in the optical waveguide and transmitting the optical signal; the optical signal provided in the optical waveguide 4A and transmitted by the optical transmitting unit from the optical signal transmitted through the optical waveguide 4A; and the optical signal to be received by the optical receiving unit. And an optical filter 5a for selecting the optical signal. Therefore, it is possible to prevent an electric signal from the optical transmitting unit from passing around to the optical receiving unit via the substrate. Accordingly, it is possible to provide an optical transmitting and receiving module having a characteristic of low interference (low crosstalk) of electric signals between transmission and reception, and having little deterioration in reception sensitivity.

It is to be noted that Embodiments 2 to 4 can be applied to the configuration of Embodiment 5 described above. Thereby, in addition to the effect of the fifth embodiment, the effects of the second to fourth embodiments can be obtained.

[0065]

As described above, according to the present invention, a light receiving element provided on a substrate and converting a received optical signal into an electric signal, one of which has the same potential as a constant potential portion, and the other has a constant potential portion A light receiving means having an output section having a potential different from that of the light receiving element and having an output means for outputting an electric signal converted by the light receiving element to the outside, and being provided on the same substrate as the light receiving element, converting the electric signal into an optical signal A light transmitting element having an input unit having a potential different from that of the constant potential unit, and having an input unit for inputting an electric signal to the light emitting element, at least between the light receiving unit and the light transmitting unit. Provided to intervene,
An optical waveguide in which an optical signal propagates, and an optical multiplexing / demultiplexing means provided in the optical waveguide for selecting an optical signal transmitted by the optical transmitting means and an optical signal to be received by the optical receiving means from the optical signal propagating in the optical waveguide. Therefore, since the cross-sectional area of the closed circuit formed by the components of the optical receiving means can be reduced, it is possible to prevent the electric signal leaked into the space from sneaking into the optical receiving means, Since it is possible to prevent an electric signal from coming into the optical receiving means via the ground, there is no electric signal sneaking, and there is little interference of the electric signal between transmission and reception (low crosstalk). There is an effect that it is possible to provide an optical transceiver module with less deterioration.

According to the present invention, since the conductive shielding plate provided between the light receiving means and the light transmitting means in parallel with the substrate and having the same potential as the constant potential portion is provided, the light transmission leaking into the space is provided. An optical transmission / reception module that shields an electric signal from the unit side and prevents it from sneaking into the optical receiving unit, so that it has a characteristic of low electric signal interference between transmission and reception (low crosstalk) and little deterioration in reception sensitivity. There is an effect that can be provided.

According to the present invention, a light receiving element provided on a substrate for converting a received optical signal into an electric signal, and an output section having one of the same potential as the constant potential section and the other having a potential different from the constant potential section A light receiving means having an output means for outputting an electric signal converted by the light receiving element to the outside; a light emitting element provided on a substrate different from the light receiving element for converting the electric signal into an optical signal; A light transmitting unit having an input unit having a potential different from that of the light transmitting unit, the light transmitting unit having an input unit for inputting an electric signal to the light emitting element; An optical waveguide through which a signal propagates, and an optical multiplexing / demultiplexing unit that is provided in the optical waveguide and selects an optical signal transmitted by the optical transmitting unit from an optical signal propagating through the optical waveguide and an optical signal to be received by the optical receiving unit. Optical transmission means Since these electric signals can be prevented from sneaking into the optical receiving means via the substrate, an optical transmitting / receiving module having a characteristic of low electric signal interference between transmission and reception (low crosstalk) and low deterioration of reception sensitivity. There are effects that can be provided.

According to the present invention, since the conductive film formed on the upper surface of the substrate and / or the upper surface of the optical waveguide and the connection means for electrically connecting the conductive film and the constant potential portion are provided, the leakage to the space is achieved. Since the electric signal from the optical transmission means can be shielded and the electric signal can be prevented from sneaking around, an optical transmission / reception module having a characteristic of low electric signal interference between transmission and reception (low crosstalk) and low deterioration of reception sensitivity. There are effects that can be provided. In addition, since the conductive film can be formed at the wafer level, the shielding structure can be easily manufactured, and the manufacturing cost can be reduced.

According to the present invention, the connecting means is arranged between the light receiving means and the light transmitting means so as to shield the input means, so that the electric signal leaking into the space from the input part of the light transmitting means is prevented. There is an effect that it is possible to prevent sneaking into the light receiving means.

According to the present invention, since the conductive film formed on the upper surface of the substrate is used as a connection pattern for connecting the optical waveguide to the substrate, a special structure for shielding and a manufacturing process are omitted. Thus, there is an effect that an optical transmitting and receiving module having characteristics of little interference of electric signals between transmission and reception (low crosstalk) and less deterioration of reception sensitivity can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an optical transceiver module according to Embodiment 1 of the present invention.

FIG. 2 is a perspective view showing an optical transceiver module according to Embodiment 2 of the present invention.

FIG. 3 is a perspective view showing an optical transceiver module according to Embodiment 3 of the present invention.

FIG. 4 is a perspective view showing a modified example of the optical transceiver module according to Embodiment 3 of the present invention.

FIG. 5 is a perspective view showing an optical transceiver module according to Embodiment 4 of the present invention.

FIG. 6 is a perspective view showing an optical transceiver module according to Embodiment 5 of the present invention.

FIG. 7 is a perspective view showing a conventional optical transceiver module.

FIG. 8 is an explanatory diagram illustrating electric signal interference between transmitting and receiving elements in the optical transmitting and receiving module illustrated in FIG. 7;

[Explanation of symbols]

1 platform substrate (substrate), 2 LD (light emitting element, light transmitting means), 3 PD (light receiving element, light receiving means),
4 optical waveguide, 4A optical waveguide (optical waveguide), 5 optical filter (optical multiplexing / demultiplexing means), 5a optical filter (optical multiplexing / demultiplexing means), 6 monitor PD (optical transmitting means), 7 preamplifier IC (optical receiving means), 8 Reception signal output lead (output unit, output unit, optical reception unit), 9 Transmission signal input lead (input unit, input unit, optical transmission unit), 10 lead frame (constant potential unit), 10a lead (constant potential unit) , 11
a wire (output unit, output means, light receiving means), 11b
Wire (input unit, input unit, optical transmission unit), 11c wire (connection unit), 12 driver IC, 13 metal shield plate (conductive shield plate), 14 metal film (conductive film), 1
4a Metal film (conductive film, connection pattern), A inlet / outlet port (optical waveguide), B Optical fiber (optical waveguide).

Claims (6)

[Claims] A light receiving element provided on a substrate for converting a received optical signal into an electric signal; and an output unit having one of the same potential as the constant potential unit and the other having a potential different from the constant potential unit, Light receiving means having output means for outputting an electric signal converted by the light receiving element to the outside; a light emitting element provided on the same substrate as the light receiving element for converting an electric signal into an optical signal; A light transmitting unit having an input unit having a different potential from the unit and having an input unit for inputting an electric signal to the light emitting element; provided at least between the light receiving unit and the light transmitting unit An optical waveguide through which an optical signal propagates; an optical signal provided in the optical waveguide, the optical signal transmitted by the optical transmitting unit from the optical signal propagating through the optical waveguide, and the optical signal to be received by the optical receiving unit. Optical multiplexing / demultiplexing means to select An optical transceiver module comprising: 2. The optical transceiver according to claim 1, further comprising a conductive shielding plate provided between the optical receiving means and the optical transmitting means in parallel with the substrate and having the same potential as the constant potential portion. module. 3. A light-receiving element provided on a substrate for converting a received optical signal into an electric signal, and an output part having one of the same potential as the constant potential part and the other having a potential different from the constant potential part, Light receiving means having output means for outputting an electric signal converted by the light receiving element to the outside; a light emitting element provided on a substrate different from the light receiving element for converting an electric signal into an optical signal; A light transmitting unit having an input unit having a different potential from the unit and having an input unit for inputting an electric signal to the light emitting element; provided at least between the light receiving unit and the light transmitting unit An optical waveguide through which an optical signal propagates; an optical signal provided in the optical waveguide, the optical signal transmitted by the optical transmitting unit from the optical signal propagating through the optical waveguide, and the optical signal to be received by the optical receiving unit. Optical multiplexer / demultiplexer to select Optical transceiver modules with and. 4. A semiconductor device comprising: a conductive film formed on an upper surface of a substrate and / or an upper surface of an optical waveguide; and connecting means for electrically connecting the conductive film and the constant potential portion. The optical transceiver module according to any one of claims 1 to 3. 5. The optical transmitting and receiving module according to claim 4, wherein the connecting means is disposed between the optical receiving means and the optical transmitting means so as to shield the input means. 6. The optical transceiver module according to claim 4, wherein the conductive film formed on the upper surface of the substrate is used as a connection pattern for connecting an optical waveguide to the substrate.