JPS62293833A - Optical input and output device - Google Patents

Abstract

PURPOSE:To provide lots of terminal equipments by allowing an optical loop network to be used for the coherent optical frequency multiplex communication system or the like using the heterodyne or homodyne using an optical frequency allocated to each terminal equipment and applying mutual communication. CONSTITUTION:Part of plural frequency lights from a 1st optical input section 1 is reflected on a mirror 5 having no wavelength dependancy, outputted to 1st optical output section 2, the remaining light is transmitted and the output side of the transmitted light is provided with an optical multiplexor means 6, which multiplexes the transmitted light and a single frequency light selected at a narrow band without giving effect onto the light of the other frequencies and inputted from 2nd optical input section 3 and outputs the result to a 2nd optical output section 4 with nearly no loss. The means 6 selects the light of single frequency from the 2nd light input section 3 without giving effect on the light of the other frequency at a narrow band and multiplexes said light and the light of plural frequencies inputted from a mirror 6 without almost any loss, and since the branch insertion loss is less and the interval of the light wavelengths is made very narrow, lots of small sized terminal equipments are inserted into the option loop network.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [1 Already Required] For example, using an optical loop 'jr Nori Wai 7, each ◇:1
．． Coherence using a heterodyne or homodyne detection method that communicates with each other using the optical frequency assigned to the yH8 end; ・In the optical frequency multi-m communication system, etc., the optical input/output device provided for each yH8 end is connected to the optical loop network. A small amount of the input light of multiple frequencies is branched and input to the receiving section, and most of it is outputted again to the optical loop network, and the m-frequency light input from the transmitting section is input from the above optical loop network. O:1; It is possible to increase the number of

[Industrial application field]

The present invention uses an optical loop network and uses a heterodyne or homodyne detection method to perform mutual communication using an optical frequency assigned to each terminal. Regarding input/output devices.

The above communication system is still in the research stage, but to explain one example using FIG. 4, each terminal 60 to 6n has a
Wavelengths λl to λn are used as transmission light sources of the transmitters 40 to 4n, respectively.
For example, when the terminal 60 transmits, the switch 50 is set to the dotted line side and the light is transmitted to the optical loop network via the optical input/output device 20.

This light is transmitted to terminals 61 to 61 through optical input/output devices 21 to 2n.
6n reception a31 to 3n, and if it is addressed to the own station, the receiver receives it.

When waiting for reception, Inoji 51 to 5n are connected to the solid line side, and the self-coherent light of the station is tuned to the wavelength of another station and heterodyned. Alternatively, it is received using the homodyne detection method. Therefore, since the S/N ratio is very good, the input level can be made small.

As for the optical input/output devices 20 to 2n used here, in terms of frequency, the interval between transmission frequencies can be narrowed, and
In order to minimize loss and to allow a large number of terminals to be inserted into an optical loop network, the light input from the optical loop network (λ1 to λn) is branched as little as possible and input to the receiver, so that most of the light is The light is output to the optical loop network, and the light of a single frequency (for example, λ1) manually input from the transmitter is selected in a narrow band without affecting the light of other frequencies input from the optical loop network. It is desirable to be able to input the signal and output it to the optical loop network with almost no loss.

[Prior art and problems to be solved by the invention] Although this optical input/output device has not been announced at present, if it were constructed using the prior art, it would be a mirror with no wavelength dependence, as shown in Figure 5. 5. Use I2.

In this case, if the reflection coefficient of the mirror 5 is made small, the light with wavelengths λl to λn outputted to the light output section 2 can be made small, and most of the light can be sent to the mirror 12 manually. However, at the mirror 12, this wavelength λI~λ
If the reflection coefficient is made smaller in an attempt to output n light to the light output section 4 with less loss, the wavelength λ input from the light input section 3
Most of the light of m is converted into IJ, and the amount of light outputted to the light output section 4 becomes very small, which causes a problem.

Therefore, the deflection direction of the light inputted from the optical input section 3 is made different from that of the light manually inputted from the mirror 5. One possible method is to increase the polarization of the light from the third stage, but in this case, there will be two types of polarization of the light output to the optical loop Neno 1 work, and when it comes to the optical input/output device used in the next stage, This method is not practical because the loss increases only for light of one polarization.

Next, as shown in FIG. 6, the light exiting the mirror 5 is inputted into the light output section 4 from the input end of the single mode optical fiber 14,
A method in which the light from the optical input section 3 is reflected by the total reflection mirror 13 at an angle θ so as not to block the light from the mirror 5, and the input to the optical fiber 14 is 0:1; that is, the optical output section 4 is manually operated. is possible, but if it is dirty, 111-Mo]・Hikari Blue
- The transmission mode of IHA 1, 1 and the output of the optical beam from the optical input section 3 are mismatched, and the loss is large, making it impractical.

If the light from the mirror 5 is not blocked and this angle θ is made small, the distance between the single mode optical fiber 14 and the mirror 13 becomes large, which is impractical.

Next, as shown in FIG. 7, using mirrors 15 and 16 provided with gratings, the light with wavelengths λ1 to λn input from mirror 5 to mirror 15 is dispersed into wavelengths jlj, and the dirt is collected by optical device 17. The wavelength λ inputted from the optical input section 3 is outputted from the optical output section 5 by manually applying light to the mirror 1G.
The light of m is reflected by mirror 18 and input to mirror 1G.
Q: Can you think of a way to output the light from the light output unit 4?

In this case, the optical wavelength resolution is about 50 ohmstrong by applying a grating, but the optical device 17
The distance between the light wavelengths must be widened so that more light can avoid the mirror ■8, and a large number of terminals can be connected to an optical lube! - There is a problem that it cannot be inserted into the workpiece, and a problem that it becomes large because the optical device 17 is used.

Means for Solving Problem C] The above problem is solved by partially reflecting the light of multiple frequencies from the first optical input section l by a mirror 5 having no wavelength dependence, as shown in FIG. The remaining light is outputted to the first light output section 2, and the remaining light is transmitted, and on the output side of this transmitted light, a narrow band selected without affecting this transmitted light and light of other frequencies is provided. This problem can be solved by a light input/output device provided with a light combining means 6 which combines light of a single frequency manually inputted from the second light input part 3 and outputs it to the second light output part 4 with almost no loss of one member.

[Effect]

According to the present invention, in the light combining means 6, the second light input section 3
It is possible to select light of a single frequency in a narrow band without affecting light of other frequencies, and it is possible to combine this light with light of a plurality of frequencies input from the mirror 6 and output it with almost no loss, Since drop/add/drop JU loss is small and the interval between optical wavelengths can be made very narrow, it is possible to make the optical loop network compact and allow a large number of terminals to be inserted into the optical loop network.

〔Example〕

FIG. 2 is a block diagram of an embodiment of the invention, and FIG. 3 is a block diagram of another embodiment of the invention.

In the figure, 1.3 is an optical input section, 2 and 4 are optical output sections, 5 is a mirror without wavelength dependence, 7 is an etalon plate, 8 is a light receiving section, 9 is a control section, 10 is a light source, and 11 is a resonance characteristic 19 is a ring-shaped optical waveguide having an optical transmission line.

Figure 2 shows that only light of a certain wavelength is very sharp, for example 1
This is an example in which an etalon plate 7 having a characteristic of selectively transmitting a wavelength difference of about one ohmstrong and totally reflecting other wavelengths is used.

The transmission properties of the etalon plate can be controlled by its thickness and thickness.

Therefore, in the case of FIG. 2, the wavelength λm input from the optical input section 3
The light reflected from the light input section 3 and the light transmitted from the mirror 5 are transmitted to the light receiving section 3 so that the light of other wavelengths is totally reflected from the mirror 5. The inclination is controlled by the control unit 9 so that the receiver is minimized.

At this time, the optical input section 3. The light output section 4 is arranged to be on a straight line.

In this way, the light of multiple frequencies from the optical input section 1 (
λ1 to λn) are reflected by the mirror 5, a small amount is outputted to the light output section 2, and most of the light is transmitted and lost to the etalon plate 7.
Light having wavelengths other than 7 m from the light input section 3 is reflected and outputted to the °ζ light output section 4.

On the other hand, the light of a single frequency (λm) from the optical input section 3 is directly input to the etalon plate 7 without affecting the light of other frequencies, is almost transmitted, and is output from the optical output section 4.

In this way, the light transmitted through the mirror 5 and the light input section 3
Both types of manually generated light can be output from the light output section 4 with almost no loss.

In the case of FIG. 3, the light from the mirror 5 is output to the output section 4, and the light of a single frequency from the light source 10 inputted from the optical input section 3 has a wavelength difference of, for example, about 1 ohm. In a ring-shaped optical waveguide 11 having selectable optical characteristics, light of other frequencies is selected without affecting it, and is manually inputted to an optical transmission line 19 and outputted to a light output section 4 with almost no loss.

As explained above, if L is inputted from the optical input section 1, a part of the light of multiple frequencies is branched: l'l, and then the optical output section 2
Most of the light is output to the optical output section 4, 1'L, and most of the single frequency light input from the optical input section 3 is input in a narrow range without affecting the light of other frequencies. Since the optical output unit 4 outputs the signal without any loss, a heterogain or homodyne detection method is used in which each terminal communicates with each other using an optical frequency using an optical loop network. If used in a Coheren I optical frequency multiplex communication method using 2, etc., it is possible to install a large number of RI;1: terminals.

〔Effect of the invention〕

As explained above in detail 1111, according to the present invention, the optical
A large number of terminals can be installed by using Pune Sotowork in a coherent optical frequency multiplexed 1S system using the Hete℃1 dyne or homodyne detection method, which communicates with each other using the optical frequency assigned to each terminal. effective.

4, 12IFj5 Noa If & Explanation Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a block diagram of an embodiment of the invention, Fig. 3 is a block diagram of another embodiment of the invention, Fig. 4 5 is a block diagram of an example of a coherent optical frequency division multiplexing communication system using an optical loop network, FIG. 5 is a line diagram of a first example of an optical input/output device, and FIG. 6 is a diagram of a second example of an optical input/output device. FIG. 7 is a block diagram of a third example of the optical input/output device.

In the figure, 1.3 is a light input section, 2.4 is a light output section, 5 is a wavelength-independent mirror, 6 is a light synthesis means, 7 is an etalon plate, 8 is a light receiving section, 9 is a control section, and 10 is a control section. A light source, 11 a ring-shaped leading waveguide having resonance characteristics, and 19 an optical transmission line.

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Claims (1)

[Claims] Light of multiple frequencies from the first optical input section (1) is partially reflected by a wavelength-independent mirror (5) and output to the first optical output section (2). However, the remaining light is transmitted, and the output side of this transmitted light is connected to the second optical input section (3), which is selected in a narrow band and does not affect the light of other frequencies. A light input/output device characterized in that it is provided with a light combining means (6) that combines input light of a single frequency and outputs it to a second light output section (4).