JPS60170805A - Optical selector - Google Patents

Abstract

PURPOSE:To narrow down intervals of respective wavelengths of multiplex light and to increase the number of multiplexed wavelengths by arranging light guides equipped with an optical switch in parallel and also arranging branching parts of the respective light guides in series, and arranging a specific spectral diffracting part at each branching part. CONSTITUTION:Light beams with wavelengths lambda1'-lambda3' are incident as parallel light on a light entrance 9 and only the light beam with the wavelength lambda3' is reflected and guided to a light guide 11. Only the light beam with the wavelength lambda2' among the light beams passed through the element 11 is reflected by the spectral diffracting element 15 and guided to a light guide 12. The light beam with the wavelength lambda3' passed through elements 14 and 15 is guide to a light guide 13. Light shield plates 18-20 provided to the respective light guides 11-13 are opened and closed selectively; the light with wavelength lambda1' passed through every optical switch is passed through elements 16 and 17, the light with the wavelength lambda2' is reflected by the element 16 and then passed through the element 17, and the light with the wavelength lambda3' is reflected by the element 17, multiplexed again, and projected from a light exit 10. Thus, the number of multiplexed wavelengths is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical selector suitable for an optical communication system that performs communication by multiplexing light of a plurality of wavelengths.

In recent years, optical transmission methods have been proposed as a new signal transmission method. Optical transmission systems use optical fibers as transmission lines and communicate using light as a medium. In the optical transmission system, for example, an optical selector is used as a means for controlling transmission or blocking of light to generate an optical signal. This light selector is formed of a light guiding member.

It has a plurality of branch light guide paths and is equipped with an optical switch for each light guide path. According to the optical selector, a spectroscopic element separates and guides the light of each wavelength in the wavelength multiplexed light to each light guide path, and an optical switch of each light guide selects whether to pass or block the light of each wavelength, and the desired signal state is set. It becomes possible to generate.

By the way, in the conventional optical selector, the following problem occurs regarding the spectroscopic element due to its structural characteristics. That is, according to a conventional optical selector, for example as shown in FIG. 1, each light guide (1).

(2), (3) optical switch (la), (2a)
, (3a), when separating and guiding light of each corresponding wavelength, each optical switch (la), (2a), (3a
) are arranged in series on the optical transmission line (0), so
In order to make each wavelength light independent, each spectroscopic element (5
), (θ), and (7) must have filter characteristics (reflection characteristics) that extract only the light of each corresponding wavelength. Therefore, as shown in FIG. 2, each wavelength λ1. Enter 2. The reflection wavelength bands (5'), (B'), and (7') in the spectroscopic elements (5), (8), and (?) for the light input 3 include only the corresponding wavelengths and overlap with each other. It must be formed so that it has no parts. In other words,
In optical wavelength division multiplexing transmission, each wavelength input 1. λ2. Input 3 light is subject to the restriction that the reflection bands of the spectroscopic elements (5), (6), and (?) must not overlap, so the wavelengths must be separated by a certain distance or more.

This means that when the wavelength pass band of the optical transmission line (4) is kept constant, the number of wavelengths multiplexed becomes smaller. As described above, the conventional optical selector configuration has a problem in that the number of wavelengths multiplexed cannot be increased.

In view of the above-mentioned problem, the present inventor has created the present invention in order to effectively solve the problem.

In the optical selector of the present invention, light guide paths equipped with optical switches that separate wavelength-multiplexed light into light of each wavelength and pass the light separately are installed in parallel, and the branch parts thereof are installed in series, so that multiplexing is possible. The purpose of this invention is to make it possible to overlap the reflection wavelength bands of each spectroscopic element that separates the separated lights, thereby narrowing the spacing between each wavelength of multiplexed light and increasing the number of wavelengths multiplexed.

In order to achieve the objective of "1", the present invention introduces light of a plurality of different wavelengths, separates the light of each wavelength into respective light guide paths using the reflection characteristics of a spectroscopic element, and In the optical selector, in which transmission or blocking of light of each wavelength is selected by an optical switch provided in the optical path, the guided light is collected again, and the light is emitted from the light exit. Branch parts of each light guide path to be taken in are arranged in series, and the corresponding above-mentioned spectroscopic element is arranged in the branch part, and the light of the corresponding wavelength and at least the reflection reflected by the immediately preceding spectroscopic element are transmitted to the above-mentioned spectroscopic element. It is constructed so that it has a reflection characteristic that can reflect the light of .

A preferred embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 3 shows an optical selector according to the present invention. Exit (8) and Idemitsu Exit (10)
), three light guide paths (11), (12), and (13) formed by branching are arranged in parallel. The optical selector (8) is made of plastic, for example, and has a light guiding function. Each light guide path (11), (12)
, (13) are arranged in series, and each branch is equipped with, for example, a dichroic mirror (interference thin film filter).
Spectroscopic elements such as (14), (15), (1G).

(17) is fixed by vapor deposition or mechanical means, and the I! a light shielding plate (1B) in which a Jl interval is formed and selects transmission or blocking of transmitted light at this interval;
(19).

(20).

] Two-distribution optical element (14), (15), (1B), (17
) has the effect of separating multiplexed light by reflecting or transmitting it depending on the wavelength. Particularly in this embodiment, when the wavelength multiplexed light consists of light of input j, input shi, and λ5,
The spectroscopic elements (14) and (17) reflect only the light of wavelength λ'l and transmit the light of other wavelengths input A and I, and the spectroscopic elements (15) and (1B) reflect only the light of wavelength λ'! , has the function of reflecting the incoming light and passing the incoming light of 5 wavelengths.

In addition, J Kibun light shielding plates (1B), (19), (20)
This operation is performed, for example, by a solenoid device (not shown), and when the light shielding plate, which moves up and down in the figure, moves within the width of the above-mentioned interval, it produces a blocking action, and when it moves outside the interval, it produces a transmitting action.

The optical selector (8) configured as shown in FIG. Further, the number of light guide paths and the number of spectroscopic elements can be arbitrarily changed depending on the number of lights to be multiplexed.

In the above, as shown in FIG. 1, for example, the light enters the light entrance (9
) for each wavelength input j, λ.

The input light 5 is separated by the action of the spectroscopic elements (14) and (15) as follows. First, only light with wavelength λ'1 is guided to the light guide path (11) by the spectroscopic element (14). Next, the light guide path (11) is set to the wavelength λ'1 by the spectroscopic element (15).
Light of wavelength λ'l is guided, but since the light of wavelength λ'l has already been reflected and removed by the spectroscopic element (14), only the light of the wavelength is guided. Furthermore, a spectroscopic element (14).

The light with wavelength input 5 transmitted through (15) passes through the light guide path (13) (
It is actually equivalent to the main railway). In this way, the light guide path (11) receives light with wavelength λ'1, the light guide path (12) receives light with wavelength input 5, and the light guide path (13) receives light with wavelength input 5.
They will pass through each. Then, each light guide path (11
), (12), and (13), the light shielding plates (18) and (19
), (20) assume appropriate operating states, and these light shielding plates (1B), (19).

By the combination of operating states (20), a combination of incoming light of each wavelength λ'1°, transmission and blocking of the incoming light is formed, and a desired signal state is generated.

Thereafter, the light that has passed through each optical switch is sent to a spectroscopic element (18
), (17), and exit light exit (10)
Light is emitted from. In this case, the light of wavelength λ'l in the light guide (11) is reflected by the spectroscopic element (17), and the light of wavelength λ'l of the light guide (12) is reflected by the spectroscopic element (16) and (17), and the light at wavelength 5 of the light guide path (13) passes through the spectroscopic elements (1B) and (+7).

According to the optical selector (8) according to the present invention, each light guide path (11), (12) is provided with an optical switch.

(13) are formed in parallel, and the branch parts for light input or light output are arranged in series, so that the multiplexed wavelength λ'! , λ, and λ5 are separated into light of each wavelength by each spectroscopic element, the second spectroscopic element (15) in the arrangement order has a filter characteristic that reflects the light of wavelength λ'1 in addition to the input wavelength. It is allowed to have. This is because the light with wavelength λ'1 has already been reflected by the spectroscopic element (14), so it does not reach the spectroscopic element (15), and even if the spectroscopic element (15) has such filter characteristics, it will not reach the light guide path. This is because the wavelength of the light guided to (12) ends up being only λ. Therefore, as shown in FIG. 5, the reflection * long band filter characteristic (1
5') is the filter characteristic (14') of the spectroscopic element (14).
) may overlap. This filter characteristic is similarly applied to the case where there are spectroscopic elements after ``No. 3''. In Figure 5, (24) shows the filter characteristic of the third spectroscopic element, which is the filter characteristic (15')
There is some overlap between the two. Since filter characteristics can be provided as shown in L, each wavelength input 'l, input
There is no need for a special wavelength spacing, and the wavelengths can be set close to each other in terms of wavelengths, so the number of wavelengths multiplexed can be increased.

FIG. 4 shows a second embodiment of the invention. In this example,
A light guide path (
21), (22), and (23) are provided in parallel, which is the same as in the above embodiment, but the overall shape of the outer periphery is approximately U-shaped (in the illustrated example, it is oriented horizontally).
It is distinctive in that it is formed in the shape of Spectroscopic element (1
4), (15), (1B), (17), light shielding plate (11
The configurations of 1), (19), and (20) are the same as in the previous embodiment. This optical selector (28) also allows the number of wavelengths to be multiplexed to be increased using the same principle as described above.

Moreover, according to this light selector (28), the light entrance (9)
Since the direction of the light output port (10) is on the same side, the direction of the light signal (Sl) becomes opposite when passing through the light selector (28). Therefore, in optical transmission, it has conventionally been difficult to reverse the direction of an optical cable in a narrow space (the optical cable cannot be bent), but this can be easily done.

As is clear from the above description, according to the present invention, in an optical selector that separately separates light of a plurality of wavelengths into each light guide path and outputs a signal, each light guide path is connected in parallel and the branch portion thereof is connected. Since they are arranged in series, it is possible to allow an overlap in the reflection wavelength bands of the spectroscopic elements, thereby achieving the effect that the number of wavelengths multiplexed can be increased.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a conventional optical selector, FIG. 2 is a diagram showing the wavelength relationship of conventional wavelength-multiplexed light and the reflection wavelength band of each spectroscopic element, and FIG. 3 is a configuration diagram of an optical selector according to the present invention. 4 is a configuration diagram of an optical selector according to another embodiment of the present invention, and FIG. 5 is a diagram showing the relationship between wavelengths of wavelength multiplexed light and the reflection wavelength bands of each spectroscopic element in the present invention. In the drawings, (1), (2), (3), (11), (12
), (13), (21). (22), (23) are light guide paths, (5), (8), (
7), (14), (15). (1B), (17) are spectroscopic elements, (5'), (8')
, (7'). (14'), (15'), (24) are the foul wavelength bands of each spectroscopic element, (Ia), (2a), (3a), (18
), (1G), (2Q) are light shielding plates, λ1. Enter 2. Enter 3.
λ′l, input and λ5 are the wavelengths of the multiplexed light. Patent applicant Honda Motor Co., Ltd. Toyo Denso Co., Ltd. Agent Patent attorney (Part 2) Patent attorney Kunihiko Ohashi Patent attorney Yu Koyama

Claims (1)

[Claims] Light of a plurality of different wavelengths is input, the light of each wavelength is separated into each light guide path by the reflection characteristics of the spectroscopic element, and an optical switch provided in the good light guide path is used to transmit or transmit each wavelength. In the optical selector that selects blocking, collects the guided light again, multiplexes it, and outputs the light. ] 2. Each of the light guide paths is arranged in parallel, and the branch parts of each light guide path for separating light are arranged in series, and the corresponding above-mentioned spectroscopic element is arranged in each of the branch parts, , a light selector having a reflection characteristic capable of reflecting light of a corresponding wavelength and at least light of a wavelength reflected by an immediately preceding spectroscopic element.