KR102841428B1 - Optical transceiver - Google Patents

Abstract

According to one aspect of the present disclosure, an optical transceiver is disclosed, including a reference tunable laser module that generates and outputs light of a reference wavelength, a first general tunable laser module that generates and outputs light of a first wavelength, and a controller that controls a tuning operation of a first wavelength of the first general tunable laser module based on information about a relationship between the reference wavelength and the first wavelength.

Description

optical transceiver

The present disclosure relates to an optical transceiver, and more particularly, to a wavelength tunable optical transceiver.

Passive Optical Network (PON) has become the core of implementation of FTTH environment and Gigabit Ethernet.

Implementing WDM-PON requires multiple optical sources with unique wavelengths. To implement multiple optical sources with different wavelengths in WDM-PON, the use of multiport-type wavelength-tunable optical transceivers capable of simultaneously outputting multiple optical signals with different wavelengths is steadily increasing.

The wavelength-tunable optical transceiver described above includes a plurality of integrated tunable laser modules, and the integrated tunable laser modules typically have the same configuration and structure. For example, the tunable laser modules each include a wavelength locker, an I/V converter, a thermistor, a TEC (thermoelectric cooler), etc. However, the wavelength locker, the I/V converter, thermistor, the TEC, etc. are not configured to generate light of a wavelength required for the tunable laser module (i.e., an assigned wavelength). Nevertheless, since they are all included in each tunable laser module, problems arise in terms of the manufacturing cost, design, and control complexity of the wavelength-tunable optical transceiver.

Korean Patent Publication No. 10-2009-0037195

In order to solve the above-described problems, the present disclosure seeks to provide a wavelength-tunable optical transceiver capable of outputting light sources having multiple wavelengths while reducing manufacturing costs and design and control complexity.

The technical problems to be solved by the technical idea of the present disclosure are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

According to one aspect of the present disclosure, an optical transceiver is disclosed, comprising: a reference tunable laser module that generates and outputs light of a reference wavelength; a first general tunable laser module that generates and outputs light of a first wavelength; and a controller that controls a tuning operation of the first wavelength of the first general tunable laser module based on information about a relationship between the reference wavelength and the first wavelength.

According to an exemplary embodiment, the information about the relationship between the reference wavelength and the first wavelength may be information indicating a difference between the reference wavelength and the first wavelength.

According to an exemplary embodiment, the difference between the reference wavelength and the first wavelength can be determined in advance by considering a temperature-dependent correlation between the reference wavelength and the first wavelength.

According to an exemplary embodiment, the optical transceiver may further include a memory storing a lookup table including information about a relationship between the reference wavelength and the first wavelength.

According to an exemplary embodiment, the reference wavelength may be a wavelength for a data transmission/reception channel or a wavelength for an auxiliary channel.

According to an exemplary embodiment, among the reference tunable laser module and the first general tunable laser module, only the reference tunable laser module may include at least one of a wavelength locker, a current-to-voltage converter, a thermoelectric cooler, and a temperature sensor.

According to an exemplary embodiment, the optical transceiver further includes a second general tunable laser module that generates and outputs light of a second wavelength; wherein the controller can control a tuning operation of the second wavelength of the second general tunable laser module based on information about a relationship between the reference wavelength and the second wavelength.

According to another aspect of the present disclosure, an optical transceiver is disclosed, comprising: at least one tunable laser module; and a controller for controlling wavelength tuning of the at least one tunable laser module by referring to a lookup table including relationship information between a preset reference wavelength and an output wavelength assigned to the at least one tunable laser module.

According to an exemplary embodiment, the relationship information may be information indicating a difference between the preset reference wavelength and the assigned output wavelength.

According to an exemplary embodiment, the difference between the preset reference wavelength and the assigned output wavelength is:

According to an exemplary embodiment, the temperature-dependent correlation between the preset reference wavelength and the assigned output wavelength may be determined in advance.

According to an exemplary embodiment, the preset reference wavelength may be a wavelength for a data transmission/reception channel or a wavelength for an auxiliary channel.

According to an exemplary embodiment, the optical transceiver further includes a reference tunable laser module that generates and outputs light of the preset reference wavelength; wherein only the reference tunable laser module may include at least one of a wavelength locker, a current-to-voltage converter, a thermoelectric cooler, and a temperature sensor.

According to embodiments of the present disclosure, in implementing a wavelength-tunable optical transceiver capable of outputting light sources having multiple wavelengths by integrating a plurality of tunable laser modules, the manufacturing cost can be reduced by simplifying the components of some of the tunable laser modules, and the design and control complexity can be lowered.

The effects that can be obtained by embodiments according to the technical idea of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the technical idea of the present disclosure belongs from the description below.

To more fully understand the drawings cited in the detailed description of the present disclosure, a brief description of each drawing is provided.
FIG. 1 is a configuration diagram of an optical communication system according to one embodiment of the present disclosure.
FIG. 2 is a block diagram of an optical transceiver according to one embodiment of the present disclosure.
FIG. 3 is a block diagram of a reference tunable laser module according to one embodiment of the present disclosure.
FIG. 4 is a block diagram of a general tunable laser module according to one embodiment of the present disclosure.
FIG. 5 is an example diagram of a wavelength lookup table according to one embodiment of the present disclosure.

The technical concept of the present disclosure is susceptible to various modifications and various embodiments. Specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the technical concept of the present disclosure to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the scope of the technical concept of the present disclosure.

When explaining the technical concepts of the present disclosure, detailed descriptions of related known technologies will be omitted if they are deemed to unnecessarily obscure the gist of the technical concepts of the present disclosure. Furthermore, numbers (e.g., "first," "second," etc.) used throughout the description of the present disclosure are merely identifiers used to distinguish one component from another.

Additionally, when a component is referred to herein as being "connected" or "connected" to another component, it should be understood that the component may be directly connected or connected to the other component, but may also be connected or connected via another component in between, unless otherwise specifically stated.

In addition, terms such as “~part,” “~device,” and “~sub-unit” described herein mean a unit that processes at least one function or operation, which may be implemented by hardware such as a processor, a microprocessor, a microcontroller, a central processing unit (CPU), a graphics processing unit (GPU), an accelerated processor unit (APU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), software, or a combination of hardware and software.

It should be noted that the division of components herein is merely a distinction based on the primary function each component is responsible for. In other words, two or more components described below may be combined into a single component, or a single component may be further subdivided into two or more components with more detailed functions. Furthermore, each component described below may, in addition to its own primary function, additionally perform some or all of the functions performed by other components. Furthermore, it should be noted that some of the primary functions of each component may be exclusively performed by other components.

Hereinafter, various embodiments according to the technical idea of the present disclosure will be described in detail.

FIG. 1 is a configuration diagram of an optical communication system according to one embodiment of the present disclosure.

Referring to FIG. 1, an optical communication system (100) according to one embodiment of the present disclosure may include an optical communication device (110), a DeMUX (DeMUX, 120) that receives an optical signal transmitted from the optical communication device (110), and remote-side optical transceivers (130) that are connected to the DeMUX (120) and receive separate individual optical signals.

An optical communication device (110) may include n optical transceivers (112-1 to 112-n) that generate individual optical signals (where n is a natural number greater than or equal to 2) and a multiplexer (111) that multiplexes n optical signals input from the n optical transceivers (112-1 to 112-n). Depending on the embodiment, the multiplexer (111) may be separated from the optical communication device (110).

The optical communication device (110) can convert input data or data received from another device into an optical signal and transmit it to the demultiplexer (120). In addition, the demultiplexer (120) is a device connected to the optical communication device (110) via an optical cable, and transmits individual optical signals assigned to each of the corresponding remote-side optical transceivers (130). The remote-side optical transceivers (130) are connected to a predetermined device.

In some embodiments, the optical communication system (10) may be applied to an optical subscriber network. In this case, the optical communication device (110) may be an optical line terminal (OLT) on the central office side. The remote-side optical transceivers (130) may be connected to any one of a remote terminal (RT), an optical network terminal (ONT) on the subscriber side, and an optical network unit.

In another embodiment, the optical communication system (100) may configure an optical transport network, which is a sub-network constituting the fronthaul segment of the wireless access network architecture. In this case, the optical communication device (110) may be a termination device on the side of a digital unit (DU) or a baseband unit (BBU) pool on the central office side. In addition, the optical transceivers (130) on the remote side may be connected to remote units (RUs) or remote radio heads (RRHs). However, the present disclosure is not limited thereto, and the technical idea of the present disclosure may also be applied to the midhaul and backhaul segments of the wireless access network architecture.

In another embodiment, the optical communication system (100) may be applied to a distributed antenna system (DAS) to eliminate shadow areas of a base station. In this case, the optical communication device (110) may be a headend unit, and remote optical transceivers (130) may be connected to an extension unit or a remote unit.

In this way, the optical communication system (100) according to the technical idea of the present disclosure can be applied to various optical communication networks implemented with optical communication devices that are located at remote locations from each other and transmit and receive optical signals through corresponding optical transceivers.

Hereinafter, with reference to FIGS. 2 to 5, the specific operation of the components of the optical communication device (110), particularly the optical transceiver (112), will be described.

FIG. 2 is a block diagram of an optical transceiver (112) according to one embodiment of the present disclosure, FIG. 3 is a block diagram of a reference tunable laser module (240) according to one embodiment of the present disclosure, FIG. 4 is a block diagram of a general tunable laser module (230) according to one embodiment of the present disclosure, and FIG. 5 is an exemplary diagram of a wavelength lookup table according to one embodiment of the present disclosure.

Referring to FIGS. 2 to 4, an optical transceiver (112) according to one embodiment of the present disclosure may include a controller (MCU, Main Control Unit) (210), a memory (220), m general tunable laser modules (230-1, 230-2 to 230-m) (wherein m is a natural number greater than or equal to 3), and a reference tunable laser module (240). Depending on the implementation, the optical transceiver (112) may further include a multiplexer (250).

First, the standard tunable laser module (240) and the general tunable laser module (230) will be described.

A reference tunable laser module (240) according to one embodiment of the present disclosure may include a temperature sensor (300), a thermoelectric cooler (TEC) (310), a wavelength locker (320), a laser controller (330), and a laser diode (340). In addition, although not shown, the reference tunable laser module (240) may further include an I/V converter capable of converting a current signal into a corresponding voltage signal, a thermistor whose resistance value changes depending on temperature, etc.

A general tunable laser module (230-1 to 230-m) according to one embodiment of the present disclosure may include a laser controller (410) and a laser diode (420). It can be seen that, unlike a reference tunable laser module (240), the general tunable laser module (230) does not include a thermoelectric cooler (TEC), a wavelength locker, an I/V converter, a thermistor, etc.

The reference tunable laser module (240) can output an optical signal of a preset nth wavelength (λn). Hereinafter, the nth wavelength (λn) is referred to as a reference wavelength. The reference wavelength can be preset, and depending on the embodiment, a wavelength for a data transmission/reception channel or a wavelength for an auxiliary channel (a wavelength for wavelength locking, etc.) can be set as the reference wavelength. Since the operation of the reference tunable laser module (240) is similar to the operation of a conventional tunable laser module, a detailed description thereof will be omitted.

The first general tunable laser module (230-1) can output an optical signal of a first wavelength (λ1) under the control of the controller (210). In addition, the second general tunable laser module (230-2) can output an optical signal of a second wavelength (λ2) under the control of the controller (210). In addition, the m-th general tunable laser module (230-m) can output an optical signal of an m-th wavelength (λm) under the control of the controller (210). Here, the first wavelength (λ1), the second wavelength (λ2) to the m-th wavelength (λm), and the reference wavelength (λn) may all be different wavelengths.

More specifically, the operation of controlling the optical signal output by the controller (210) based on the relationship between a preset reference wavelength (λn) and the assigned wavelength required for each of m individual general tunable laser modules (230-1 to 230-m) is described.

First, information about a reference wavelength (λn) is stored in the memory (220), and information about the relationship between the reference wavelength (λn) and each of the first to mth wavelengths (λ1 to λm) may be stored in the form of a lookup table. Meanwhile, in FIG. 2, the memory (220) is illustrated as being a separate configuration from the controller (210), but the memory (220) may also be a configuration included in the controller (210).

The controller (210) can control the laser controller (410) included in the first general tunable laser module (230-1) based on information about the relationship between the reference wavelength (λn) and the first wavelength (λ1) stored in the lookup table of the memory (220), and the laser controller (410) can cause the laser diode (420) to output a first optical signal corresponding to the first wavelength (λ1).

In the same way, the controller (210) can control the laser controller (410) included in the m general tunable laser module (230-m) based on information about the relationship between the reference wavelength (λn) stored in the lookup table and the m wavelength (λm), and the laser controller (410) can cause the m optical signal corresponding to the m wavelength (λm) to be output from the laser diode (420).

Referring to FIG. 5, a wavelength lookup table according to one embodiment of the present disclosure is illustrated. The wavelength lookup table may include information on the relationship between a first wavelength (λ1) and a reference wavelength (λn), information on the relationship between a second wavelength (λ2) and a reference wavelength (λn), or information on the relationship between an m-th wavelength (λm) and a reference wavelength (λn).

Information about the relationship between the above wavelengths and the reference wavelength may be information indicating the difference between the wavelengths. For example, as illustrated in FIG. 5, information indicating that the first wavelength is greater than the reference wavelength by a (λ1 = λn + a), the second wavelength is greater than the reference wavelength by b (λ2 = λn + b), and the mth wavelength is greater than the reference wavelength by k (λm = λn + k) may be included in the wavelength lookup table.

The difference between the wavelengths (a, b, etc.) may be a value determined in advance in consideration of, for example, a correlation with temperature, and the wavelength lookup table may also include information related to the temperature. For example, the wavelength lookup table may be preset as a=αΔT+x1, b=αΔT+x2, k=αΔT+xm. Here, α may be a preset correlation coefficient. In addition, ΔT may be a difference value from a preset reference temperature. Information about the reference temperature may be stored in advance in the memory (220), and the reference tunable laser module (240) may sense the current temperature through the provided temperature sensor (300), and the controller (210) may generate a difference value (ΔT) between the sensed temperature and the reference temperature. In addition, x1 to xm may be a preset offset. Such temperature-related information may also be included in the wavelength lookup table and stored in advance in the memory (220). Additionally, information regarding the size of the reference wavelength may be stored in advance in the memory (220).

Accordingly, the controller (210) can read information about the relationship between the reference wavelength stored in the memory (220) and the wavelength required for the general tunable laser modules by referring to the wavelength lookup table, and can control the wavelength tuning of the optical signal so that each of the first general tunable laser module (230-1) to the mth general tunable laser module (230-m) has the wavelength required based on the read information.

In other words, the controller (210) can control each laser controller (410) of the general tunable laser modules, and each laser controller (410) can set the output light wavelength value of the general laser diode so that it has the output light wavelength value set (or assigned) according to the control of the controller (210).

The nth optical signal output from the reference tunable laser module (240) can be converted into modulated nth optical data by combining it with transmission data in a corresponding modulator and input to the MUX (250).

Likewise, the first optical signal output from the first general tunable laser module (230-1) to the m-th optical signal output from the m-th general tunable laser module (230) can be converted into modulated first optical data to m-th optical data by being combined with transmission data in a corresponding modulator, and each of the first optical data to m-th optical data can be input to the MUX (250).

The multiplexer (250) of the optical transceiver (112) can multiplex the first optical data to the nth optical data and output them to the multiplexer (111) of the optical communication device (110). The multiplexer (111) of the optical communication device (110) can multiplex optical signals input from a plurality of optical transceivers (112-1 to 112-n) and transmit them to corresponding remote-site optical transceivers (130) via the demultiplexer (120) through an optical cable.

As described above, the controller (210) can set the wavelength value of the optical signal output from the general tunable laser module (230-1 to 230-m) using the wavelength lookup table stored in the memory (220).

As a result, each of the plurality of general tunable laser modules (230-1 to 230-m) may not include any other components (e.g., TEC, Wavelength Locker, Thermistor, etc.) other than the laser controller (410) and laser diode (420) for generating an optical signal.

Accordingly, it is obvious that the optical transceiver (110) according to the embodiments of the present disclosure can have a simple configuration and further reduce the manufacturing cost.

In the above, it is assumed and explained that the reference tunable laser module (240) outputs an optical signal of a preset reference wavelength, but the reference tunable laser module (240) can also generate and output light of a corresponding wavelength under the control of the controller (210).

For example, the wavelength lookup table of the memory (220) may include information on the relationship between the reference wavelength and the wavelength (i.e., the nth wavelength) to be output from the reference tunable laser module (240). In this case, the controller (210) may perform tuning for the reference wavelength using the information stored in the wavelength lookup table of the memory (220). That is, the controller (210) may control the laser controller (330), and the laser controller (330) may set the output light wavelength value of the reference laser diode (340) according to the control of the controller (210).

Above, the technical idea of the present disclosure has been described in detail with reference to various embodiments, but the technical idea of the present disclosure is not limited to the above embodiments, and various modifications and changes are possible by a person having ordinary knowledge in the art within the scope of the technical idea of the present disclosure.

100: Optical communication system
110: Optical communication device
120: Demux
112, 130: Optical transceiver

Claims (12)

A reference tunable laser module that generates and outputs light of a reference wavelength;
A first general tunable laser module that generates and outputs light of a first wavelength; and
A controller that controls a tuning operation of the first wavelength of the first general tunable laser module based on information about the relationship between the reference wavelength and the first wavelength;
Including,
Information about the relationship between the reference wavelength and the first wavelength is information indicating the difference between the reference wavelength and the first wavelength,
An optical transceiver, wherein the difference between the reference wavelength and the first wavelength is determined in advance by considering the temperature-dependent correlation between the reference wavelength and the first wavelength.
delete delete In the first paragraph,
A memory storing a lookup table including information on the relationship between the reference wavelength and the first wavelength;
An optical transceiver further comprising:
In the first paragraph,
The above reference wavelength is an optical transceiver, which is a wavelength for a data transmission/reception channel or a wavelength for an auxiliary channel.
In the first paragraph,
An optical transceiver, wherein among the above-mentioned reference tunable laser module and the above-mentioned first general tunable laser module, only the above-mentioned reference tunable laser module includes at least one of a wavelength locker, a current-to-voltage converter, a thermoelectric cooler, and a temperature sensor.
In the first paragraph,
A second general tunable laser module that generates and outputs light of a second wavelength;
Including more than,
An optical transceiver, wherein the controller controls a tuning operation of the second wavelength of the second general tunable laser module based on information about the relationship between the reference wavelength and the second wavelength.
At least one tunable laser module; and
A controller that controls wavelength tuning of at least one tunable laser module by referring to a lookup table including relationship information between a preset reference wavelength and an output wavelength assigned to the at least one tunable laser module;
Including,
The above relationship information is information indicating the difference between the preset reference wavelength and the assigned output wavelength,
An optical transceiver, wherein the difference between the preset reference wavelength and the assigned output wavelength is determined in advance by considering the temperature-dependent correlation between the preset reference wavelength and the assigned output wavelength.
delete delete In paragraph 8,
An optical transceiver wherein the preset reference wavelength is a wavelength for a data transmission/reception channel or a wavelength for an auxiliary channel.
In paragraph 8,
A reference tunable laser module that generates and outputs light of the preset reference wavelength;
Including more than,
An optical transceiver comprising only the above-mentioned tunable laser module, at least one of a wavelength locker, a current-to-voltage converter, a thermoelectric cooler, and a temperature sensor.