JPH03209226A - Light competition control circuit - Google Patents

Abstract

PURPOSE:To directly execute competition control without converting an optical signal to an electric signal by providing a beam synthesization splitting means, competition detecting means, beam delay means and beam synthesizing means. CONSTITUTION:The light power 1/100 of the optical signal to be supplied through a light highway 3a (3b) is monitored by a beam splitter 20 with a splitting ratio 1:100 and it is detected according to this monitored light power whether competition is executed or not. The level of the monitored light power is converted to the electric signal by an O/E converter 21 and this electric signal is supplied to a 2X2 optical switch 22 composed of niobic acid lithium waveguides 22a and 22b and electrodes 22c and 22d. Then, it is controlled whether the optical signal is passed or not. Thus, without converting the optical signal to the electric signal, the competition control is executed while maintaining the optical signal as it is.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical competition control circuit that can perform competition control while maintaining high speed without converting optical signals into electrical signals. .

[Prior Art] A conventional competition control circuit was configured as shown in FIG. In this figure, la and lbl are input optical highways that function as optical transmission lines, and 30a and 30b are O/E
(Optical/T1 air) conversion circuit, 3l is a Puffer memory constituted by an electrical memory. The operation of the conventional competition control circuit 40 configured as described above will be explained with reference to FIGS. 16 and 17. Human power light highway I a.
Data A and B transmitted on Ib are independent of each other, and at a certain timing, the data may or may not exist. For example, if there is data, such as a packet signal, there is an optical signal,
If there is no data, there will be no signal such as a "0" level. As shown in FIG. 16, when data A and B exist at the same time on the human power optical highway [a, IbJ2], the competition control circuit 40 delays and outputs one of the data. do. On the other hand, the 17th
As shown in the figure, when data A exists rY only on either one of the input optical highways 1a and Ib, this data A is output without delay. In this case, the contention control circuit 40 converts the optical signal to the O/E conversion circuit 30a. 30b
After converting it into an electrical signal, the buffer memory 3
Write down 1. For writing to the buffer memory 31, for example, the speed is doubled, and if there is data on the input optical highway 1a at the timing of the first half, it is written, and at the timing of the second half, data is written on the input optical highway 1b. If so, write it.

Contention control is performed by reading at highway speed.

[Problems to be Solved by the Invention] By the way, the above-described conventional competition control circuit 40 cannot perform competition control at the optical signal level, so it is not possible to perform competition control at the optical signal level. Competitive control is performed after the optical signal on Ib is once converted into an electrical signal by the O/E conversion circuits 30a and 30b.This conversion operation limits the overall operating speed, and as a result, the competitive control There was a problem in that it was not possible to achieve high speed.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide an optical competition control circuit that can directly perform competition control without converting optical signals into electrical signals.

[Means for Solving the Problems] The present invention provides that, when a plurality of optical signals with different wavelengths arrive simultaneously via a plurality of optical transmission lines, a specific optical signal among them is outputted preferentially, and the other optical signals are outputted with priority. In the optical competition control circuit, the optical competition control circuit outputs a temporally delayed optical signal, the optical multiplexing/splitting means for multiplexing and branching the plurality of optical signals, and the power of the optical signal output from the optical multiplexing/splitting means. a conflict detection means for detecting a mirror match based on the content, and outputs the optical signal to a first optical transmission line when there is a conflict, and outputs the optical signal to a second optical transmission line when there is no conflict; and an optical delay means for delaying the optical signal output to the first optical transmission line according to each wavelength, and an optical signal delayed by the optical delay means and output to the second optical transmission line. and an optical multiplexing means for multiplexing and outputting the optical signals.

[Effect 1. According to the configuration in item L, when a plurality of optical signals with different wavelengths are multiplexed and branched by the optical multiplexing/branching means and then manually input to the combination detection means, a conflict is detected based on the power of the optical signals. be done. When a conflict is detected, the optical signal output from the conflict detection means to the first optical transmission line is delayed by the optical delay means according to its wavelength, and then outputted via the optical multiplexing means. .

[Examples] Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a first embodiment of the present invention. In this figure, 2 is a 2×2 optical star coupler that combines the optical signals of wavelets λ and λ guided by input optical highways Ia and 1b, respectively, and branches them into two; 3a and 3b are The wavelength output from optical star coupler 2 (
It is an optical highway that guides two optical signals of λ, +λ, )/2, respectively. Reference numeral 4 denotes a HP P (high power pass) filter, which has a characteristic of passing an optical signal supplied via the optical highway 3a when the power of the optical signal is above a certain level. Reference numeral 5 denotes an LPP (low power bus) filter, which has a characteristic of passing an optical signal supplied via the optical highway 3b when the power of the optical signal is below a certain level. 6 is H PP filter 4
This is an optical multiplexer that multiplexes the optical signal supplied via the optical fiber cable 6 and the optical signal output from the LPP filter 5; The optical signal multiplexed at 7 is output to an output optical highway 8.

An example of the configuration of the HPP filter 4 and LPP filter 5 is shown in FIG. 2.

As shown in this figure, 1/+00 of the optical power of the optical signal supplied via the optical highway 3a (3b) is monitored by the optical branch 420 with a branching ratio of 1:100, and this monitored optical power is used to compete. It is detected whether the Then, the monitored optical power level is converted into an electrical signal by the O/E converter 2I, and this electrical signal is transmitted to the lithium diobate (LiNbOs) optical waveguides 22a, 22.
b and electrodes 22c and 22d to control whether or not to pass the optical signal.

In this case, since the transmitted optical signal itself is not O/E converted, only the optical power is detected regardless of the optical signal format (analog or digital), bit rate, etc. and LPP filter 5 can be configured.

Next, as another example of the structure of the HPP filter 4, as shown in FIG. 3, a traveling wave type laser diode 23 may be used. In this figure, 23a is an active layer, 23b is an insulating region, and 23c is a current injection region. Such a laser diode 23 has diode-like characteristics between the human input optical signal and the output optical signal, as shown in FIG. 4, depending on the conditions of the injection current. That is, when the optical power exceeds a certain threshold value, the output optical signal is emitted.

Furthermore, as another example of the structure of the L P P filter 5, a twin stripe type laser diode 24 can be used, as shown in FIG.

As shown in FIG. 6, such a laser diode 24 has the following characteristics between an input optical signal and an output optical signal. That is, when the power of the input optical signal is gradually increased from 0, it passes up to a certain value, and then decreases. Furthermore, if you increase the power, it will pass again. Here, if the optical input power is set to a certain value and is limited to the following, LPP characteristics will be exhibited.

Next, the light propagation characteristics of the optical fiber cable 6 mentioned above are as shown in FIG. In this figure, the horizontal axis shows the wavelength [μm] of light within the optical fiber cable 6, and the vertical axis shows the relative delay time (ns), which is the delay time per unit length.
/ka). As shown in this diagram, for example, the wavelength!
．． The optical signal of 5 [μ angle] has a wavelength! ．． For every I (lv) transmitted for an optical signal of 3 [μm], approximately 2 (ns
) I will be late.

FIG. 8 shows a case where an optical signal A with a wavelength λ+(-1.3 μm) and an optical signal B with a wavelength λ, (=1.5 μm) are multiplexed and transmitted through the optical fiber cable 6. Signal A
are transmitted earlier than the optical signal R, and as a result, they are output at different timings on the time axis.

Next, the operation of the first embodiment described above will be explained.

First, a case will be described in which optical signals simultaneously arrive at the same timing via input optical highways Ia and 1b.

These two optical signals are combined and split into two by the optical star coupler 2, and then sent to the HP via highways 3a and 3b, respectively.
It is transmitted to the P filter 4 and the LPP filter 5. HP
Since the power of the optical signal is greater than a certain threshold level in the P filter 4, the optical signal passes through. FIG. 9 shows the operation of this HPP filter 4 when optical signals of wavelengths λ and λ overlap. In this case, the two optical signals are divided into a DC (direct current) component and an AC (alternating current) component, and the combined power exceeds the threshold of the I-[P l) filter 4, so it can be seen that there is an error. . on the other hand,
In the LPP filter 5, as shown in FIG. 10, since the optical input power is greater than a certain level, no output light is output.

Then, by transmitting the optical signal output from the HPP filter 4 through the fiber cable 6, the wavelength λ
, for example, are output at different timings on the time axis J2, as shown in FIG. Further, the output optical signal of the optical fiber cable 6 and the output optical signal of the LPP filter 5 (actually, the signal is 0 and does not exist) are combined by a multiplexer 57 and output onto the destination highway 8.

As described above, the two optical signals competing on the input optical highways Ia and 1b are output at different timings on the time axis.

On the other hand, if the optical signal is present on either one of the input optical highways 1a and 1b, for example, the input optical highway I
If only an optical signal of wavelength λ exists on a, then H P
The P filter 4 does not pass the input light because the power of the input light is small. Moreover, the LPP filter 5 is the first! As shown in the figure, the light passes through because the optical power is smaller than a certain value. Then, only the optical signal that has passed through the LPP filter 5 is guided to the multiplexer 7, and only the optical signal that has passed through the LPP filter 5 is output onto the output optical highway 8 without delay.

In this way, according to the above-described embodiment, when optical signals conflict, the optical signals are output with shifted positions on the time axis, and when there is no conflict, the optical signals are output as they are. If the HPP filter 4 or the PP filter 5 is implemented using a laser diode element, the optical signal can also be amplified.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, the output of the HP I) filter 4 (if there is a conflict, an optical signal obtained by combining optical signals with wavelengths λ1 and λ) is divided into wavelengths λ by a demultiplexer 12.
Optical fiber cable 6 which is split into optical signals of 1 and λ and has different lengths a. 6b on the time axis, multiplexed by the optical multiplexer 17, and then guided to the optical multiplexer 7.

In this embodiment, optical fiber cable 6a. By changing the length of the optical signal 6b, it is possible to actually give a larger delay to the propagation time of the optical signal, so it is possible to shift the position on the time axis with a relatively short fiber.

Next, a third embodiment of the present invention will be described with reference to FIG. 13. As shown in this figure, the optical competition control circuit according to the first embodiment described above is provided in each of the n stages from the first steno 81 to the nth stage Sn, and The output terminals of the preceding stages S, ~Sn-1 are connected to one input terminal, and the first
The other input end of stage S and subsequent stages S, ~Sn is an open end. Thereby, as shown in FIG. 14, even when optical signals A1 to A arrive successively, signal B can be multiplexed with a maximum delay of n time slots.

In each of the above-mentioned embodiments, the case where competitive control is performed for two optical signals supplied via two optical human-powered highways [a and Ib] was explained as an example, but when When performing contention control, for example, A. B. C
First of all, if you want to control highway conflicts? After controlling the competition between A and B, it is sufficient to control the competition with C.

[Effects of the Invention] As explained above, according to the present invention, it is possible to perform competition control as an optical signal without converting the optical signal into an electrical signal. It is possible to achieve faster speeds compared to conventional ones, and it also increases the transmission speed of optical signals and analog signals. The effect is that extremely high-speed competition control can be performed regardless of the signal format, such as digital.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a block diagram showing the configuration of a first embodiment of the present invention, and Fig. 2 shows a related example of an HPP filter and an LPP filter applied to the same embodiment. FIG. 3 is a perspective view showing another configuration example of the HPP filter applied to the same embodiment, and FIG. 4 is a graph showing the characteristics of the HPP filter.
FIG. 5 is a perspective view showing the configuration of the LPP filter applied to the same example, FIG. 6 is a graph showing the characteristics of the same LPP filter, and FIG. 7 is an optical fiber applied as the optical delay means to the same example. A graph showing the propagation characteristics of the cable, Fig. 8 is a conceptual diagram for explaining the delay operation of the same destination fiber cable, Fig. 9 is a graph for explaining the operation of the HPP filter of the same example, Part Figures 1 and 11 are graphs for explaining the operation of the LPP filter of the same embodiment, Figure 12 is a block diagram showing the configuration of the second embodiment of the present invention, and Figure 13 is a graph showing the configuration of the second embodiment of the present invention. 14 is a block diagram showing the configuration of the embodiment 3, FIG. 14 is a conceptual diagram for explaining the operation when contention control is performed over multiple time slots according to the same embodiment, and FIG. 15 is a diagram showing conventional contention control. The block diagrams illustrating the circuit configuration, FIGS. 16 and 17, are conceptual diagrams for explaining the operation of the competition control circuit. I a, I b... Input optical highway, 2.
...Hikari Star Coupler, 3a, 3b...Hikari Highway, 4...1
4P filter, 5... LPP filter, 6... Optical fiber cable, 7... Optical multiplexer, 8... Output optical highway.

Claims (5)

[Claims] (1) When multiple optical signals with different wavelengths arrive at the same time via multiple optical transmission lines, a specific optical signal among them is output preferentially and other optical signals are delayed in time. The output optical contention control circuit includes an optical multiplexing/splitting means for multiplexing and branching the plurality of optical signals, and detecting a competition based on the power of the optical signal output from the optical multiplexing/splitting means, a conflict detection means for outputting the optical signal to a first optical transmission line if there is a conflict, and outputting the optical signal to a second optical transmission line if there is no conflict; an optical delay means for delaying the optical signal according to each wavelength; and an optical delay means for combining and outputting the optical signal delayed by the optical delay means and the optical signal output to the second optical transmission line. An optical competition control circuit comprising: an optical multiplexing means for performing (2) The optical competition control circuit according to claim 1, wherein the competition detection means is constituted by a laser diode. (3) The optical delay means includes a demultiplexer that demultiplexes an optical signal of a specific wavelength and an optical signal of other wavelengths, and delays the optical signal of a specific wavelength demultiplexed by the demultiplexer. Claim characterized in that it is constituted by a delay line and a multiplexer that multiplexes and outputs the optical signal delayed by the delay line and the optical signal of another wavelength output from the demultiplexer. 1
The optical competition control circuit described. (4) The optical delay means has a delay time per unit length.
2. The optical competition control circuit according to claim 1, wherein the optical competition control circuit is comprised of optical elements that differ depending on the wavelength. (5) A plurality of stages of the optical competition control circuit according to claim 1 are provided, and one input end of each stage after the first stage is connected to the output end of the previous stage, and the other input end of each stage after the first stage is an open end. An optical competition control circuit characterized by: