JPH02109005A - Optical signal processor - Google Patents

Abstract

PURPOSE:To offer an optical signal processor which scarcely causes a processing error, and also, has a structure which can be manufactured easily by providing plural branch paths running along a first waveguide on a positional relation corresponding to a distance obtained by converting a time position of each signal of the respective time divisions to a distance position. CONSTITUTION:An optical signal transmission body 30 is formed integrally by quartz glass so as to contain a straight line-like main waveguide 31 of prescribed width, and four branch ports 331 - 334 formed like parallel branches at every prescribed interval in the same side direction thereof, and in gates 351 - 354 of its tip parts, sub-waveguides 371 - 374 are formed by the same quartz glass. When the optical signal transmission body works as an optical signal separating device, an optical signal which is brought to time division multiplex transmits through a first waveguide 31, and allowed to branch into every signal by the branch ports 331 - 334 provided on the positional relation corresponding to a distance obtained by converting the time position of each signal in the time division state of the optical signal to the distance position. In such a manner, each optical signal is outputted in a form which is brought to signal separation from each of the sub-waveguides 371 - 374 through the optical gates 351 - 354.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical signal processing device, for example, for separating or multiplexing optical signals in time division multiplexed signal transmission. The present invention relates to an optical signal processing device that functions as a multiplexing device.

[Conventional technology]

Conventionally, optical signal processing apparatuses for separating or multiplexing optical signals have been constructed as shown in FIG.

First, a case will be described in which the optical signal processing device shown in FIG. 3 works as an optical signal separation device.

Now, pulses 1. are multiplexed at time intervals as shown in FIG.・2.・31 ・41 ・12 ・22 ・3
2 ・4□ ・l:l ・23 ......
It is assumed that an optical signal (tiplex) is input to the fiber 11. The optical time-division multiplexed signal manually input from the outside via the fiber 11 is branched into, for example, four optical signals by the splitter 3. Here, the power of the optical time division multiplexed signal is equally distributed in the splitter 13, and the output ports 15. ~15. The signal is supplied to the delay device 17 through each of them.

This delay device 17 is composed of loop-shaped fibers 19 each having a different length, and provides a different time delay to each optical signal supplied thereto. Now, let L be the time required for an optical signal to pass through the length of one loop of the loop-shaped fiber 19. Therefore, the number of loops of the loop-shaped fiber 19 is determined by the output port 1 of the brancher 13.
5. and one output port 21 of the delay device 17,
2 between the output port I5□ of the branching device 13 and the output port 21z of the delay device I7, and the output port 15 of the branching device 13
1 and the output port 21° of the delay device 17 are three. Note that the output port 154 of the branching device 13 and the output port 214 of the delay device 17 are directly connected by a fiber without forming a loop. In this way, delay device 1
By setting the number of loops of the loop-shaped fiber 19 at 7 to be different from each other, the output ports 21 to 2
From 14, optical signals of pulse trains that are time-shifted are output.

FIG. 5(A) shows the pulse train of the input signal, FIG. 5(B) shows the four pulse trains at the output ports 15I to 154 of the splitter 13, and FIG.
The pulse trains from 214 to 214 are shown arranged in chronological order.

In this way, the output ports 21° to 21. of the delay device 17.
The output signal obtained from the gate 23 enters the gate 23. here,
As shown in FIG. 5(c), the output port 2 of the delay device 17
14. In the order of the output signals of 21y, 2]□, and 211, the pulse train becomes a temporally advanced signal state.

The opening/closing operation of the gates 23 is controlled so that one cycle is a time interval 4L, which is four times the time, and the gates 23 are opened all at once only for a time t out of a time 4t. However, the detailed configuration and operation of the gate 23 are known.

Now, for example, if the gate 23 is opened for a period of time at the time position indicated by the * mark in FIG. 5(a), the fiber 25.
The optical signal outputted from 254 is in the state of a pulse train as shown in FIG. In other words, when looking at the time 4L of a certain period, pulses 1. ．． 2. ．． 3
．． ．． 4. is obtained. Moreover, at time 4t of the next cycle, pulses 1□, 2□ 3□ 4 are sent from the fibers 251 to 254.
2 is obtained. Therefore, four fibers 251-254
The four optical signals outputted from the four optical signals are separated time division multiplexed signals. With such a configuration and operation, optical time division multiplexed signals are separated.

Furthermore, when the optical signal processing device shown in FIG.
5i to 254. Now, a pulse train (pulse 11) repeated at a time interval of 4 pulses as shown in FIG.
・１１ ・１゜■４ ・・・・・・Pulse 21
・2□ ・2.・24 ・・・・・・2 pulses 3□
・３□ ・３．・34 ......and pulse 4
1-4□ ・4. The four optical signals shown as 4i......) are sent to the fiber 25. ~Supplied from the 254 side,
The gates 23 are opened all at once over a period of time 4L. Here, the pulse width of the pulse train is permissible up to the time interval during which the gate 23 is opened. Different time delays are provided by each of the four fibers of the delay device 17, and the four signals are combined in the splitter 13. Therefore, a signal is outputted to the fiber 11 in a form similar to that shown in FIG. 4 (FIG. 5(A)). However, fiber 11
Looking at the time series in , pulse 431 ・21 ・
II ・4□ ・3□ ・2□ ・1□ ・4, ・3.
......... By performing the reverse operation of separation in this way, it is possible to obtain an optical signal multiplexed signal that is multiplexed optical signals.

Problem to be solved by the invention C] By the way, in the conventional optical signal processing device described above, the splitter 13
．． Since it consists of three types of parts: delay device 7 and gate 23, the input and output ports of each part must be connected accurately and with good reliability in order to keep optical power loss low. did not become. Furthermore, when the optical signals to be multiplexed and demultiplexed become faster, the length of the fiber used in the delay device 17 becomes extremely short, and adjusting it to an accurate length requires a lot of processing time and advanced technology. It takes. Therefore,
There are many difficulties involved in creating a device that precisely matches the delay time of the optical signal pulse train to an integral multiple of time 12, which results in variations in product accuracy, making it difficult to use for high-speed signal processing. There is a problem in that signal processing errors occur.

The present invention has been created in view of the above points, and it is an object of the present invention to provide an optical signal processing device having a structure that causes fewer processing errors even in demultiplexing processing of high-speed optical time division multiplexed signals and is easy to manufacture. It is an object.

[Means to solve the problem]

The optical signal processing device of the present invention that achieves the above object includes a first waveguide formed to be elongated so that an optical signal can be transmitted. Further, a plurality of branch paths are provided along this first waveguide path. The positional relationship of the intervals between these multiple branching paths is determined by the distance obtained by converting (converting) the time position of each signal into a distance position in the time division state when multiplexing or separating optical signals to be transmitted. Compatible. Further, an optical gate is formed in each of the plurality of branch paths, and a second waveguide extends from each of the optical gates.

[For production]

When the optical signal processing device of the present invention works as an optical signal separation device, time-division multiplexed optical signals are manually transmitted through the first waveguide. Depending on the positional relationship of each branch path corresponding to the distance obtained by converting the time position of each signal in the time division state of the optical signal to a distance position, each signal in the time division state of the transmitted optical signal is branched. . Each optical signal is output from each of the plurality of second waveguides via the optical gate in a signal-separated form.

Furthermore, when the optical signal processing device of the present invention works as an optical signal multiplexing device, each of the plurality of optical signals is input to the corresponding second waveguide, and each branch path in which the optical gate is formed is inputted. enter. The positional relationship of each branch path corresponds to the distance obtained by converting the time position of each signal in the time division state of the optical signal to a distance position, so the first waveguide where each optical signal obtained via the branch path gathers In this case, the time relationship is in a time division state. Therefore, in the first waveguide, a plurality of optical signals are transmitted and output in a multiplexed signal state.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 shows the configuration of an optical signal processing device in an embodiment of the present invention.

In FIG. 1, an optical signal transmission body 3o is manufactured by forming a quartz glass layer of a certain thickness on a silicon substrate by, for example, the CVD method, and then etching it. This optical signal transmission body 30 includes a main waveguide 31 extending linearly with a constant width,
It is integrally formed of quartz glass so as to include four branch boats 33I to 334 formed in parallel branch shapes at regular intervals on the same side of the main waveguide 31. Branch bow) 33. ~33□ have the same length, and a gate 35. ~354 are formed.

These gates35. ~354 is a sub-waveguide Bf extended for inputting and outputting optical signals! ! 31. ~374 are made of the same quartz glass. In addition, branch boat 33. ~3
34 and the sub waveguides 371 to 374 are game) 35. ~35
A predetermined interval is provided for the main waveway 311 and branch boat 3.
31 to 334 and sub waveguide 37. ~374 are simultaneously formed of quartz glass. After that, branch boat 33. ~3
3. and sub waveguides 371-37. Gate 351~
35.

In an optical signal processing device having such a structure, the main waveguide 3
An input/output end 39 is formed at one end (the left end in the figure) of 1.

By the way, branch boats 33 branched at regular intervals,
33. A main waveguide 31 with an attached waveguide and a sub-waveguide 37 which requires accurate positioning. 374 and branch boats 331 to 334 and sub waveguide 37. Gate 35.~374. Examples of techniques for forming ~354 include, for example, Transactions of the Institute of Electronics, Information and Communication Engineers, Volume C, page 685;
No. 5.1988, etc. According to this quartz optical circuit manufacturing method, branching boards 1-33. ~3
34, main waveguide 31 and sub waveguides 371-374, gate 35. ~354 can be formed.

For example, branch boat 33. ~334 and sub-waveguide 37
．． ~374 interval is approximately 20 mm when demultiplexing 10 Gbps ultra-high-speed optical time division multiplexed signals, and 20 Gbps
In the case of s, it is about 10 mm. Therefore, according to the quartz optical circuit manufacturing method described above, the quartz optical circuit can be formed with sufficient dimensional accuracy.

Next, the operation of the embodiment having the above configuration will be explained separately in "the case j when the device functions as an optical signal demultiplexer" and "the case j when the optical signal multiplexer functions as an optical signal demultiplexer".

Also, Fig. 4 shows the optical time division multiplexed signal input to the optical signal processing device, Fig. 5 shows the branching/delaying state of signal pulses in the separation process of the optical signal processing device, and after passing through the gate of the optical signal processing device. Please also refer to FIG. 6, which shows the signal pulse arrangement state of .

j; 8. To separate the incoming optical time division multiplexed signal, first, the optical time division multiplexed signal shown in FIG. input.

The state of the optical signal that has progressed within the main waveguide 31 is determined at a certain point in time (
For example, if you look at the time position marked * in Figure 5 (C), the second
It will look like the figure. In other words, the pulse 1. The branch boat 33 □ which is spaced apart from the branch boat 33 by a predetermined distance has a pulse 21, and the branch boat 33:l has a pulse 3.
Pulse 4 exists in each of the 9 branch ports h33n. At that time, for example, at the time position marked * in FIG. 5(C), the gate 35. 354 are opened all at once, pulses l, 2, 3 .
4 is obtained. That is, at time t of time interval 4L of a certain period, pulse l8. Pulse 21 from another sub-waveguide 37□, sub-waveguide 37. from pulse 31
．． Pulse 4 from sub waveguide 374. are obtained respectively.

Also, at time t of the next cycle, the sub waveguide 37. From pulse 17. Pulse 2□ from sub waveguide 372, sub waveguide 37
．． Pulse 3□ is obtained from the sub-waveguide 374, and pulse 4□ is obtained from the sub waveguide 374, respectively. Therefore, the four sub-waveguides 37+ to 37
．． As shown in FIG. 6, an aligned separation pulse train (pulse ll ・1
．． J ・14 ・・・Pulse 21 ・2□
・23 ・2i ・・・・・・Pulse 3132 ・
3.・34 ......and pulse 41 ・4□
4,・44...) is output.

On the other hand, when optical signals are multiplexed, it can be achieved by completely reversing the signal flow described above.In other words, multiplexing of optical signals can be achieved by completely reversing the signal flow described above. Each of the signals may be supplied from each of the corresponding sub-waveguides 37. to 374, and an optical signal output may be obtained from the input/output end 39 of the main waveguide 31.

Now, a pulse train (pulse 11 ・I7 ・1.・I...
...) to the sub-waveguide 37. Then, the optical signal of another pulse train (Pulse 2.・2□ ・2.・24 ・・・・・) is sent to the sub waveguide 37□, and the pulse train (Pulse 31 ・3
□ ・33 ・34 ・・・・・) optical signals are sent to the sub-waveguide N373 as a pulse train (pulse 4.・42 ・4, ・
4a...) are respectively input to the sub waveguides 374.

Gates 351 to 354 are connected at time t( out of a period of time 4L)
When the main waveguide 31 opens all at once, the branch boat 3 opens as shown in FIG.
3. In this case, pulse 4 appears in pulse 11 branch port 33□, pulse 21 branch port 333, pulse 31 and pulse 4 in branch port 334, respectively. In this way, the main waveguide 31 has a form in which four optical signals are combined. However, from each branch boat 33 to the input/output end 39 of the main waveguide 31
The time it takes for each optical signal to reach the input/output end 39 differs depending on the distance to the input/output end 39. Therefore, when viewed in chronological order, at the input/output end 39 of the main waveguide 31, pulses 431 ・21 ・11 ・42 ・multiplexed at time intervals are generated.
3t ・2□ ・1□ ・4, ・3. A time division multiplexed signal consisting of a pulse train of . . . is output. The time division multiplexed signal obtained at the input/output terminal 39 has a signal state as shown in FIG. By performing the reverse operation of separation in this manner, an optical signal multiplexed signal obtained by multiplexing optical signals can be obtained.

As is clear from the above description, the optical signal processing device according to the embodiment of the present invention is composed of waveguide-type components that can easily obtain high-precision dimensions, and furthermore, the optical signal processing device according to the embodiment of the present invention is Since the optical power loss is small due to the small number of parts, even if the signal becomes high speed, the occurrence of signal processing errors due to deviations in pulse intervals, reduction in received light level, etc. is extremely reduced.

As described above, the optical signal processing device of this embodiment has a simple configuration, can be manufactured using a method with established mass production technology, and has almost no deviation in pulse interval even when the signal speed becomes ultra-high.
Due to its low loss of optical power, it is used as a multiplexing/demultiplexing device in optical LAN systems that require ultra-high-speed optical time-division multiplexing signal processing. In that case, highly reliable system processing can be easily performed. In other words, the most important feature of the optical signal processing device according to this embodiment is the use of a single waveguide type component that has both an optical branching function and an optical delay function. This point differs from conventional optical signal processing devices in which the splitter and delay device have to be manufactured separately and then recombined.

Note that the branch boat 3 formed integrally with the main waveway 31
The number of 3 does not matter. In addition, the main waveway 31° branch boat 3
3. The sub waveguide 37 may be made of a material other than quartz glass,
The manufacturing method is not limited to the CVD method and etching.

Furthermore, those skilled in the art will easily guess that the present invention has various modifications.

〔Effect of the invention〕

As mentioned above, according to the present invention, the configuration is simple,
Even if the optical signals to be separated or multiplexed are ultra-high speeds, there is almost no deviation in the signal interval, so it is possible to easily perform multiplexing and five-separation processing on ultra-high speed optical signals.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an optical signal processing device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a signal passing state in the embodiment of the present invention shown in FIG. 1, and FIG. 3 is a diagram of a conventional optical signal processing device. A configuration diagram showing the processing device, FIG. 4 is an explanatory diagram of the optical time division multiplexed signal input to the optical signal processing device, and FIG. 5 is an explanatory diagram of the branching/delaying state of signal pulses in the separation process of the optical signal processing device. , FIG. 6 is an explanatory diagram of the signal pulse array state after passing through the gate of the optical signal processing device. In the figure, 11.25 is a fiber, 13 is a splitter, 15.21 is an output port, 17 is a delay device, I9 is a looped fiber, 23.35 is a gate, 30 is an optical signal transmission body, 31 is a main waveguide, 33 is a branch boat, and 37 is a sub waveguide. Figure Figure Figure Figure Figure Number 6 ΔL zero + Figure (A) (σ) Iro 54 million! , (c) Figure

Claims (1)

[Claims] (1) A first waveguide formed to be elongated so that optical signals can be transmitted, and when multiplexing or separating the optical signals to be transmitted, converting the time position of each signal into a distance position in the time division state. a plurality of branching paths provided along the first waveguide at intervals having a positional relationship corresponding to the distance between the two; an optical gate formed in each of the plurality of branching paths; and a plurality of optical gates extending from the optical gate. What is claimed is: 1. An optical signal processing device comprising: a plurality of second waveguides that are connected to each other;