JPS6384330A - Automatic optical switch - Google Patents

Abstract

PURPOSE:To realize a high-speed switching action and to increase the number of optical branching points, etc., by driving an optical switch while monitoring the address code added to an optical signal and at the same time transmitting other data when the optical signal data is not available. CONSTITUTION:A part of the incident light OPTIN is transmitted through a half mirror 30 and converted into electric signals by an O/E converter. The address code added to the front of an optical signal is always monitored and a coincidence signal is delivered from an address code coincidence detecting circuit 36 if said address code is equal to a specific code. Then an optical switch 40 is controlled and the branched light is switched to OPTOUT1 from OPTOUT2. While an AND gate 48 is opened via an AND gate 44 and other data are turned into the branched light OPTOUT3 via a beam splitter 54 in case no signal OPTIN is available nor a specific code is not detected by a carrier detecting circuit 42, the circuit 36 and an inverter 46. The incident light OPTOUT3 is not divided into two pieces and a switch constitution where a prism, etc., are not moved mechanically is secured. In such a way, a high-speed switching action is ensured together with increase of optical branching points.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an automatic optical switch, and more particularly to an automatic optical switch that changes the optical path of an optical signal depending on the content of an address code added before a data signal of the optical signal. Regarding switches.

[Conventional technology]

Conventionally, an optical branching device as shown in FIG. 3 and an optical switch as shown in FIG. 4 have been used to branch optical signals of an optical LAN. The optical splitter divides the optical signal sent from the optical fiber cable IOA into two by a half mirror 14 or a prism through the Selfoc lens 12A, and the divided optical signal is transmitted through the respective Selfoc lenses 12B and 12C. The optical fibers are then sent to the optical fiber cables IOB and IOC.

Further, the optical switch is configured to send an optical signal sent from the optical fiber cable 1°D through the lens 16D, refract it by the triangular prism 18A, and send it to the optical fiber cable 10 through the lens 16E. When switching the optical path of the optical signal, the prism 20 is mechanically driven to intervene between the lens 16D and the triangular prism 18A. Then, the optical signal irradiated from the lens 16D is refracted by the prism 20, made to enter the triangular prism 18B, and irradiated to the optical fiber cable IOF via the lens 16F.

[Problem that the invention seeks to solve]

However, since conventional optical splitters split the input optical signal into two, the optical output loss at the time of splitting increases, and the optical L A
The number of N branch points is limited.

In addition, since conventional optical switches mechanically move prisms to switch optical paths, the switching speed is slow and cannot be used for branching optical LANs. The problem is that it can only be used as .

The present invention was made to solve the above problems, and by reducing loss during optical branching and increasing switching speed, it is possible to increase the number of optical L A NO branching points and perform high-speed multiplex communication. The purpose of this invention is to provide an automatic optical switch that can

[Means for solving problems]

In order to achieve the above object, the present invention provides an automatic optical switch for branching optical signals, which includes an address code detection means that constantly detects an address code added before a data signal of an optical signal, and an optical path of an optical signal. an optical switch for changing the optical path of the optical signal by driving the optical switch when the address code detected by the address code detection means is a specific address code, and an optical switch control means for driving the optical switch to change the optical path of the optical signal; data signal detection means for detecting the presence or absence of a signal; and data for transmitting a data signal when the address code detected by the address code detection means is not a specific address code and no data signal is detected by the data signal detection means. a signal transmitting means;
It is configured with the following.

[Effect]

According to the present invention, the address code detection means detects the address code added before the data signal of the optical signal, and the optical switch control means changes the optical path when the address code matches a specific address code. The switching speed of the switch can be increased. Furthermore, since the data signal transmission means transmits the data signal when the address code detected by the address code detection means is not a specific address code and no data signal is detected by the data signal detection means, malfunctions and other signals may occur. collision can be avoided.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a block diagram of an automatic optical switch according to the invention.

The input optical signal ○PTIN is sent to an O/E (photoelectric) converter 32 consisting of a pin photodiode, an avalanche photodiode, etc. using a half mirror 30 or a beam splitter.
The light is branched to the side 0PTIN+ and the light OP T +N□ is branched to the optical switch 40 side.

The branch light 0PTINI detects the address code added before the data signal in the input optical signal op'r, N which is predetermined for operating the optical switch 40. By setting the clock frequency of the data signal (carrier) to a low speed, the transmission speed of the address code can be made smaller than the transmission speed of the data signal, so that the branch light oPT+□ can be reduced. Therefore, the ratio of optical signal outputs from the half mirror 30 is 1:n (
n>>1)=OPTINI: Can be set to 0PTIN2.

The branched light 0PTI)I+ is converted into an electrical signal by the O/E converter 32, and the converted electrical signal is sent to the amplifier 34.
is amplified by The amplified electrical signal is detected to match a predetermined address code for driving the optical switch 40 by the address code/number configuration circuit 36. When the address codes match, a match signal (high level bell) is transmitted to the switch control circuit 38, and the switch control circuit 38 drives the optical switch 40 using the electro-optic effect or magneto-optic effect, and the optical path is changed to 0PTou. It is formed on the 0PTou side from A2 to A and receives an optical signal. If the address codes do not match, the switch control circuit 3 is output from the address code/number output circuit 36
8, the optical switch 40 is driven by the switch control circuit 38, and the optical path is set to 0.
The light is formed on the PTOU 2 side, passes through the beam splitter 54, and is output to the OP T 0UT 3 side.

Next, the transmission of data signals will be explained in detail.

The input optical signal OPT,N is input to the half mirror 3 as described above.
0 or beam splitter to split light 0PTIHI on the ○/E converter 32 side and branched light 0PTIHI on the optical switch 40 side.
Branched to PTIH□.

The branched light 0PTIN is converted into an electrical signal by the 0/E converter 32 and amplified by the amplifier 34. The carrier detection circuit 42 detects whether or not a data signal is inserted after the address code in the amplified electrical signal. In this case, the input optical signal OP T + N is not received and the signal is determined, but only the presence or absence of the data signal is detected.
PTINI can be small. When the carrier detection circuit 42 detects that there is no data signal, the carrier detection circuit 42 outputs a signal (H level) indicating no data signal, and the ■ level signal is transmitted via the AND gate 44 and the terminal 62. input to the node.

On the other hand, the electrical signal amplified by the amplifier 34 is also input to the address code/number output circuit 36, and the address code/number output circuit 36 determines whether the predetermined address code for the optical switch 40 matches. When transmitting a data signal, the address code is the address code of another optical switch.
A mismatch signal (L level) is output from the multiple output circuit 36, and the optical switch 40 is output by the switch control circuit 38 described above.
is driven, and an optical path is formed on the 0PTOIIT2 side.

Further, the mismatch signal (L level) from the address code/number configuration circuit 36 is output to the inverter 46 , where it is converted to H level and input to the AND gate 44 .

The AND gate 44 receives the H signal from the carrier detection circuit 42.
The gate is opened by the H level signal and the H level signal from the inverter 46, and the 11
A level signal is output.

In the AND gate 4B, when a signal is transmitted from the terminal node connected to the branch point of the optical switch to another node, a data signal is input from the terminal 60, and the AND gate 44
The gate is opened by the H level signal from the terminal 60 and the data signal from the terminal 60, and the data signal from the terminal 60 is output to the amplifier 50.

The amplifier 50 amplifies the data signal from the terminal 60,
The amplified data signal is converted into an optical signal by an Elo (lightning) converter 52, and the converted optical signal is outputted from the optical switch 40 by a dome splitter 54 as output light 0PTOUT2.
It combines with the signal light of the address code sent from the address code and outputs it to the output light 0PTOL+3 side.

When the carrier detection circuit 42 detects that there is a data signal, an L level signal is output to the AND gate 44. Therefore, the AND gate 44 and the AND gate 48 are closed, and the data signal from the terminal 60 is not output from the ant gate 48, and only when the carrier detection circuit 42 detects that there is no data signal, the data signal from the terminal 60 is
Data from 0 is transmitted.

FIG. 2 shows a circuit in which the circuit shown in FIG. 1 is monolithically integrated on a substrate 5B. Note that a beam splitter 64 is used instead of the half mirror 30 to split the human-powered optical signal. 56 is a waveguide.

From the above, according to this embodiment, since it is an optical switch that utilizes the electro-optic effect or the magneto-optic effect,
High-speed operation of approximately 0 psec is possible. Therefore, the optical path is switched immediately after several address codes are output, and high-speed multiplex communication is possible. In addition, human power optical signal OPT
, N is branched light OP T I N l and OPT+Nz
When branching, the branching ratio is 1:n (where n>>
l)=OPTINI:0PTIN□, so the loss in the optical switch is small. Therefore, compared to the conventional optical splitter as shown in FIG.
The loss when switching the optical path is similarly small, and when transmitting, the data signal is transmitted only when there is no data signal after another address code, so collisions with transmission signals from other optical switches can be avoided and the communication line reliability is guaranteed.

〔Effect of the invention〕

As explained above, according to the present invention, the loss of the input optical signal can be reduced and branched, so the number of branching points can be increased without using repeaters, and the switching speed of the optical switch can be increased. This enables high-speed multiplex communication. In addition, it constantly detects the address code of the input optical signal, drives the optical switch only when it matches the address code of the optical switch itself, switches the optical path to receive the data signal, and when transmitting, it follows the address code of other optical switches. By transmitting a data signal only when there is no data signal, malfunctions and collisions of other signals can be avoided, and multiplex communication of nuns becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an automatic optical switch according to an embodiment of the present invention, FIG. 2 is a circuit diagram showing an example in which automatic optical switches according to the present invention are integrated on a substrate in a thousand-dimensional manner, and FIG. FIG. 4 is a schematic diagram showing the configuration of a conventional optical branching device. FIG. 4 is a schematic diagram showing the configuration of a conventional optical switch. 30... Half mirror 1 40... Optical switch, 54... Beam splitter. Figure 2 Figure 3

Claims (1)

[Claims] (1) In an automatic optical switch that branches optical signals,
an address code detection means for constantly detecting an address code added before a data signal of an optical signal; an optical switch for changing the optical path of the optical signal; and an address code detected by the address code detection means for detecting a specific address code. an optical switch control means for driving the optical switch to change the optical path of the optical signal; a data signal detection means for detecting the presence or absence of a data signal in the optical signal; and an address detected by the address code detection means. An automatic optical switch comprising: data signal transmitting means for transmitting a data signal when the code is not a specific address code and the data signal is not detected by the data signal detecting means.