JPS6340121A - Optical path switching control device - Google Patents

Abstract

PURPOSE:To suppress a loss of an optical signal, and to execute a switching operation at a high speed by constituting the titled device so that a control means outputs a control signal to a switching means, switches an optical path, and photodetects a data signal, when an address code which has been added in front of the data signal coincides with an address code which has been added to the switching means. CONSTITUTION:A branch light beam to an optical/electric transducer 21 side by a half mirror 31, namely, the first input optical signal IN1 is converted to an electric signal by the optical/electric transducer 21 and amplified by an amplifier 22, and inputted to an address code coincidence detector 23. A coincidence detection to an address code which has been added in advance, of each optical switch is executed, and when each of them coincides, the address code coincidence detector 23 outputs a coincidence signal to a switch controller 24. The switch controller 24 drives the optical switch concerned 10, switches an optical path from OUT2 to OUT1 and makes a data signal branch. When the address code is discrepant, the optical switch 10 is not driven, the data signal is outputted from the optical path OUT2, and it is made to transmit through the optical switch 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical path switching device used in optical communications.

[Conventional technology]

LAN (local area network) using optical communication
In this case, optical path switching of optical signals is performed using an optical branching device or an optical switch.

An optical splitter divides an optical signal into two using a half mirror or prism, as shown in Figure 3, and an optical switch mechanically drives a prism to switch the optical path, as shown in Figure 4. be.

[Problem that the invention seeks to solve]

However, these optical path switching devices cannot sufficiently support high-speed multiplex communication that handles a large amount of information.

In other words, an optical splitter always divides the input optical signal into two, resulting in a large optical signal loss.The number of branch points in an optical LAN is limited due to the optical output, and optical switches are mechanically Since the optical path is switched between the two, the switching speed is low, making it unsuitable for branching an optical LAN, and can only be used as a switch for switching to another line in the event of a line failure.

Therefore, an object of the present invention is to reduce the loss during branching of an optical path switching device and to increase the switching speed to enable high-speed multiplex communication.

[Means for solving problems]

Therefore, the present invention constantly monitors the address code added before the data signal, and according to this address code,
It is characterized in that the optical path is switched to receive the data signal.

Specifically, as shown in FIG. 1, the optical path switching control device of the present invention includes a switching means for switching the optical path, and an address whose transmission speed is lower than the transmission speed of the data signal, which is added before the data signal. control means that constantly monitors the address code and outputs a control signal to the switching means to switch the optical path and receive the data signal when the address code and the address code added to the switching means match. It consists of

[Effect]

As a result, when the address code added before the data signal matches the address code added to the switching means, the control means outputs a control signal to the switching means to switch the optical path and receive the data signal. High-speed switching operation can be performed while suppressing signal loss.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an overall configuration of an embodiment of the present invention. In the figure, 10 is an optical switch corresponding to the switching means of the present invention, and 20 is a control circuit corresponding to the control means of the present invention.

The optical switch 10 is an element that utilizes an electro-optic effect or a magneto-optic effect, and includes L iT e O3, L tNb0
This is a known method in which the optical path is switched by applying an electric field to the 3rd grade or a magnetic field to the YIG, etc., and the speed is several tens of ps.
It is capable of high-speed switching operation of ec (10-" seconds), and the input optical signal (IN in Fig. 2) is branched by the half mirror 31 to the second input optical signal (I in Fig. 2).
Nt> is input. Note that a beam splitter may be used in place of the half mirror 31 described above. This optical switch 10, together with a control circuit 20, is similar to a conventional optical branching device.
A plurality of stages are combined to form an optical LAN.

The control circuit 20 includes an optical/electrical converter (07E converter, PIN-PD, APD, etc.) 2 to which the first input optical signal (INI in FIG. 2) branched by the half mirror 31 is input.
1, an amplifier 22 that amplifies the output signal from this optical/electrical converter 21, and constantly monitors the amplified signal from the amplifier 22, and an address code added in advance to each optical switch 10, and a first input. When the address code in the optical signal I N r matches, the address code match detector 23 outputs a match signal, and upon receiving the match signal from the address code match detector 23, sends a switching signal to the corresponding optical switch 10. It is composed of a switch controller 24 that outputs.

Since the address code before the data signal, which is constantly monitored, is not a signal containing a large amount of information like the data signal, its transmission speed should be lower than the transmission speed of the data signal. Therefore, the optical output of the branched light to the optical/electrical converter 21 can be reduced, and the output of the branched light to the optical/electrical converter 21 can be reduced.
The branching ratio of the optical output of l:n(n 1)-IN, :IN
, can be.

As a result of the above configuration, the light branched by the half mirror 31 to the optical/electrical converter 21 side, that is, the first input optical signal IN+, is converted into an electrical signal by the optical/electrical converter 21 and then sent to the amplifier. 22 and input to the address code coincidence detector 23. Address code match detector 23
Detects a match with the pre-added (set) address code of each optical switch 10, and outputs (transmits) a match signal to the switch controller 24 when they match.

The switch controller 24 drives the corresponding optical switch 10 to switch the optical path from OUT z to OUT+ in the figure and branch the data signal.

When the address codes do not match, the optical switch 10 is not driven, and the data signal is output from the optical path OUT z and transmitted through the optical switch 10 .

In this way, since the address code transmission speed is lower than the data signal transmission speed to reduce the optical output, the branching ratio at the half mirror 31 is 1:n (n 1) =
IN+:IN, and the loss due to branching is 1/n+1 (
n1), and the loss of the optical switch 10 can be reduced.

In addition, the optical switch 10 can be a switch that utilizes an electro-optic effect or a magneto-optic effect, so
A high-speed switching operation of sec can be performed.

FIG. 2 shows an example in which optical switches and control circuits similar to those of the first embodiment described above are integrated on a monolithic substrate 40. In addition, in the figure, 32 is a beam lifter, 33.34.
35, 36 and 37 are waveguides. By integrating the entire optical path switching control device in this way, it is possible to easily construct an optical LAN.

Although specific embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and includes various embodiments within the scope of the claims. This will be clear to those skilled in the art.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to reduce the loss during optical path switching, so it is possible to increase the number of branch points without using a repeater. Multiplex communication can be made possible.

Further, since the optical path is switched depending on the match of the address codes, malfunctions and signal collisions can be avoided, and multiplex communication of nuns can be performed.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the overall configuration of an embodiment of the present invention, and FIG.
The figures show an integrated embodiment of the optical path switching control device of the present invention, FIG. 3 shows a conventional optical splitter, and FIG. 4 shows a conventional optical switch. 10------One light switch (switching means) 20...
- Control circuit (control means) 21 - - Optical/electrical converter 22 - - Amplifier 23 - 111 - Address code - Failure detector 24 -
---Switch controller 31--11-Half mirror- Applicant Toyota Motor Corporation Fig. 2

Claims (1)

[Claims] 1. The switching means that switches the optical path and the address code added before the data signal that is lower than the transmission speed of the data signal are constantly monitored, and the address code added to the switching means and the address code added before the data signal are An optical path switching control device comprising: control means for outputting a control signal to the switching means so that the optical path is switched and the data signal is received when the address code added to the optical path matches the address code added to the optical path switching means.