JPH03223705A - Optical multiplexing/demultiplexing device and optical multiplexing/demultiplexing module - Google Patents

Abstract

PURPOSE:To reduce crosstalk by providing another waveguide closely to one waveguide in parallel and forming a reflecting means on the exit end surfaces of both the waveguides. CONSTITUTION:The directional coupler 51 functions as a 1st wavelength selecting element and light signal with wavelength lambda1 is lead out through a core 31; and a core 32 which propagates a light signal with wavelength l2 demultiplexed by the directional coupler 51 functions as the wavelguide A and a core 33 which is provided closely to the waveguide A in parallel functions as the waveguide B. A directional coupler 52 is provided with a reflecting film 6 as the reflecting means on one end surface side of the two parallel waveguides A and B. The light signal with the wavelength lambda2 which is propagated in the core 32 as shown by an arrow A is coupled with the core 32 through the reflecting film 6 and propagated as shown by an arrow 74. Thus, the waveguides A and B constitute the directional coupler, so respective light signals demultiplexed by the 1st wavelength selecting element 51 are projected at a sufficient distance. Consequently, the crosstalk is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical multiplexer/demultiplexer and an optical multiplexer/demultiplexer module for wavelength division multiplex transmission.

[Background Art] Wavelength division multiplexing transmission technology in optical fiber communications is important in making communication systems more economical.

In the above-mentioned wavelength division multiplex transmission, a wavelength division multiplex transmission module equipped with an optical multiplexer/demultiplexer, a light emitting hydroelectric light receiving element, a pintail fiber, and an electronic circuit is an essential optical device.

The present inventor has proposed a module for wavelength division multiplexing transmission having a configuration not shown in FIG. 8 (Kuraku Imoto, "Waveguide Type Optical Multiplexer/Demultiplexer", Hitachi Cable, No. 8. PP).

19-24.1989), this consists of an optical multiplexer/demultiplexer 201 with a waveguide structure on two substrates, a pingtail fiber 202 is connected to one side of the waveguide, and a pingtail fiber 202 is connected to the opposite side. This is a combination of a semiconductor laser LD and a light receiving element PD. Further, an electronic circuit 203 for driving a semiconductor laser and a light receiving element is also mounted on the substrate.

[Problems to be Solved by the Invention] In order to realize the configuration shown in FIG. 8 using the current technology, the semiconductor laser and the light receiving element must be mounted in the form of a chip. However, in that case, it is necessary to hermetically seal the entire module to improve the reliability of the chip, but the technology for hermetically sealing the entire module is currently not possible.

Currently, we have no choice but to use a semiconductor laser package in which the semiconductor laser and lens are mounted on a mount and hermetically sealed, and a photodetector package in which the photodetector and lens are mounted on the mount and hermetically sealed. The height, width, and length of the package are approximately several 1111.

Therefore, as shown in FIG. 9, the interval 2G between the waveguide 204 that couples one semiconductor laser LD and the waveguide 205 that couples the light receiving element PD must be set to several 1u11 or more. However, this interval 2G If we take the number 1 or higher, the total length of the waveguide is 2011, as shown in Figure 10.
11 or more, which makes it difficult to downsize.

There is also the problem that as the total length increases, the waveguide propagation loss also increases.

Furthermore, since the semiconductor laser parameter and the light-receiving element package are located close to each other, there is a concern that crosstalk may deteriorate due to the interference of electrical signals. Particularly, when performing high-speed, high-bandwidth signal transmission (>several hundred Hb/s), this crosstalk becomes a serious problem.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above, and to provide a compact optical multiplexer/demultiplexer and optical multiplexer/demultiplexer module for wavelength division multiplexing transmission with less crosstalk.

[Means for Solving the Problems] A basic form of the present invention is that in an optical multiplexer/demultiplexer that separates optical signals of at least two different wavelengths, a first wavelength selection element separates optical signals of at least two different wavelengths. Another waveguide B is provided close to and parallel to the waveguide A through which the optical signal of at least one wavelength that has been demultiplexed is propagated, and an exit end face of the waveguide A and the waveguide B is provided. An optical multiplexing/demultiplexing device configured to couple the demultiplexed optical signal of at least one wavelength into the waveguide B by forming a reflecting means in the waveguide B, and propagate in a direction opposite to the propagation direction in the waveguide A. It is a container (Claim 1).

The reflecting means may be a reflective film (claim 2), or an interference film having a function of reflecting only the optical signal of at least one of the demultiplexed wavelengths and passing optical signals of other demultiplexed wavelengths. Filter (Claim 3) or the waveguide A
and an optical mirror surface (claim 4) in which the exit end face of the waveguide B is mirror-finished.

A directional coupler can be used as the first wavelength selection element (claim 5), and the waveguide B side that guides the split optical signal of at least one wavelength is further provided with a directional coupler. It is possible to develop a configuration in which a second wavelength selection element is connected in series, which selectively passes only optical signals of at least eleven wavelengths and suppresses optical signals of other divided wavelengths. (Claim 6).

Next, the optical multiplexer/demultiplexer module of the present invention (claim wa):
In the optical multiplexer/demultiplexer of the above-mentioned basic form, a light-receiving element package or a light-emitting element package is arranged on each waveguide terminal side where optical signals of at least two different wavelengths are demultiplexed and output. . The light-receiving element package may be a single light-receiving element, or may include a light-receiving element with a lens or a light-receiving element with a built-in electronic circuit. The light-emitting element may be a single light-emitting element, or may include a light-emitting element with a lens or a light-emitting element with a built-in electronic circuit (claim 8).

In this optical multiplexer/demultiplexer module, it is preferable that an interference film filter is provided in front of the light receiving element to pass only an optical signal of a desired wavelength (claim 9), and that at least two optical signals of different wavelengths are provided. Preferably, at least one of the light-receiving element barrier gauge and the light-emitting element barrier gauge connected to the waveguide terminal side where the optical signal is demultiplexed and output is connected via an optical fiber (claim 10).

Regarding the optical multiplexer/demultiplexer, the above basic form (claim 1) can be further developed as follows.

That is, a configuration in which another waveguide B is provided close to and parallel to the waveguide A, and reflecting means are formed at the exit end faces of the waveguides A and B,
At least one further cascade connection can be made on the waveguide B side (Claim 1■), and at least two optical multiplexers/demultiplexers of the above basic form (Claim 1) can be combined to produce at least three different wavelengths. (Claim 12) In this optical multiplexer/demultiplexer, a light receiving element is provided on the waveguide terminal side where optical signals of at least three different wavelengths are demultiplexed and pressed. By arranging either a barrier gauge or a light emitting element package, an optical multiplexer/demultiplexer module is obtained (claim 13).

[Function] In the optical multiplexer/demultiplexer of claim 1, another waveguide B33 is provided on the waveguide A32 side through which the demultiplexed optical signal of at least one wavelength propagates, close to and parallel to this. A reflecting means is formed on the exit side end surfaces of the two waveguides 8A and B, and the demultiplexed optical signal that has propagated in the waveguide 32 of A toward the reflecting means is directed to the waveguide B in the opposite direction. The waveguides A and B constitute a directional coupler so as to couple and propagate within the waveguide 33. For this reason, each optical signal demultiplexed by the first wavelength selection element (51) is emitted to a location where it can be sufficiently used.

This reduces crosstalk. Further, since the waveguides are configured to be folded back by the reflective film, the length of each waveguide is shortened, and it is possible to achieve low loss and miniaturization.

In claim 3, the reflecting means includes an interference film filter (161
, 162), so for example, the wavelength λ1λ2λ3
When λ2 .
Only λ3 is reflected, and the other divided optical signals of wavelength λ1 are passed. Therefore, the wavelength λ1 component can be removed and the wavelength λ2λ3 can be separated, and crosstalk can be further reduced.

In the optical multiplexer/demultiplexer of claim 6, the wavelength λ from the reflecting means
The optical signal of 2λ3 is propagated to the second wavelength selection element (53), where the wavelength λ1 is suppressed (see FIG. 2).

The optical multiplexer/demultiplexer according to claim 7 includes the following three forms.

That is, when the light receiving element barrier gauge (12) is arranged at each of the waveguide terminals (31, 33) ill where optical signals of at least two different wavelengths are distributed and output, the optical demultiplexer module Therefore, the light emitting element balance gauge (1
When 1) is arranged, it becomes an optical multiplexer module. Furthermore, a light-receiving element barrier gauge (12) is mounted on one side of the waveguide terminals (31, 33), and a light-emitting element barrier gauge (11) is mounted on the other side.
When installed, it becomes an optical module for bidirectional transmission (
In these three forms, the element contained in the light receiving element (light emitting element) baggage is either a single light receiving element (light emitting element) or a light receiving element with a lens (see Figure 3).
It can be arbitrarily determined whether the light receiving element (light emitting element) is a light emitting element) or the light receiving element (light emitting element) with a built-in electronic circuit. However, it is preferable to provide an interference film filter in front of the light-receiving element that allows only optical signals of the desired wavelength to pass through, and to connect the light-receiving element baggage or light-emitting element package via optical fibers (91, 92>). .

The optical multiplexer/demultiplexer of claim 11 has a multi-stage configuration consisting of waveguides A and B and reflecting means, and is suitable for reducing the degree of crosstalk. The optical multiplexer/demultiplexer of claim 12 is a combination of two or more structures consisting of waveguides A and B and reflecting means, and is suitable for demultiplexing three or more wavelengths (see Fig. 4).
, Claim 13 provides that on the waveguide terminal side of those branched outputs,
Either a light-receiving element package or a light-emitting element package is arranged, and a module or bidirectional transmission optical module that divides or multiplexes a desired number of wavelengths can be obtained.

[Example] Fig. 1 shows an example of the waveguide type optical multiplexer/demultiplexer of the present invention.
3(a) is a side view, and FIG. 2(b) is an A-AlEIi plane view thereof.

This optical multiplexer/demultiplexer is for demultiplexing (or multiplexing, or multiplexing/demultiplexing) optical signals of two wavelengths λ1 and λ2.

First, the configuration will be explained. A substrate 1 (semiconductor such as Si, GaAs, glass with a refractive index control dopant added to SiO2, 5if2, sapphire, etc.) has a refractive index n.
A low refractive index layer 2 (glass made of SiO2°5iOz doped with a dopant for controlling the refractive index) is deposited thereon, and a substantially rectangular core 31.32 having a refractive index of nw (nw>nh) is deposited thereon.
and 33 are formed. A cladding layer 4 having a refractive index nc (nc < nw ) is covered on the core and the low refractive index layer. The core and cladding layers are made of SiO2° or SiO2 with B as a dopant for controlling the refractive index.
It is composed of at least one of P, Ge, Ti, A, Cl, Ta, Zn, Sb, etc.

The directional coupler 51 used has a characteristic of selectively splitting the optical signal of wavelength ^2 and passing the optical signal of wavelength λ1 as is. This directional coupler 51 functions as a first wavelength selection element, and the optical signal of wavelength λ1 is extracted through the core 31. Wavelength λ demultiplexed by directional coupler 51
A core 32 that propagates the optical signal of No. 2 functions as a waveguide A, and a core 33 that is provided close to and parallel to this waveguide A.
functions as waveguide B.

The directional coupler 52 has a reflective film 6 as a reflecting means on one end surface side of the two parallel waveguides A and B, and the length of the coupling portion of the two parallel waveguides is set to the coupling length of the directional coupler 51. The length of the section is approximately 1/2 of the length p.

That is, as shown by arrow 73, the optical signal of wavelength λ2 propagated in core 32 is coupled into core 33 via reflection film 6, and propagated as shown by arrow 74.
This is a directional coupler that has wavelength selectivity for an optical signal of so-called wavelength λ2.

The optical signal having the wavelength λ1 is reflected by the reflection WA6 and propagates inside the core 32 again in the opposite direction to the arrow 73.

Here, instead of the reflective film 6, an interference film filter may be used as the reflecting means, which exhibits a passing characteristic for the optical signal of the wavelength λ1, and exhibits a passing characteristic for the optical signal of the wavelength λ2.

Furthermore, if the exit end faces of waveguide A and waveguide B are made perpendicular and optically mirror-finished, fairly good reflective end faces can be ensured without providing the reflective film 6 or interference film filter. This method is economical because it can be realized more easily than, for example, by optically polishing or dry etching the end face. If the waveguide end face is realized by the above method, the end face (1) will be reflected by the air with a refractive index of 1 and the waveguide with a refractive index of approximately 1.462, and the optical signal will be reflected in the opposite direction with a reflection close to 90°. can be propagated to

Next, an outline of the operation of the waveguide type optical multiplexer/demultiplexer shown in FIG. 1 will be explained.

The optical signals with wavelengths λ1 and λ2 that have propagated as shown by arrow 71 enter the core 31, and only the optical signal with wavelength λ2 is selectively distributed by the directional coupler 51 and propagates in the core 32 as shown by arrow 73. do. The optical signal of wavelength λ1 is sent to the directional coupler 51
The light passes through the waveguide as it is and is emitted out of the waveguide as shown by an arrow 72. The optical signal of wavelength λ2 that has propagated as shown by arrow 73 is further divided by directional coupler 52, propagates within core 33 as shown by arrows 74 and 75, and is emitted to the outside of the waveguide.

Note that in the configuration shown in FIG. 1, the wavelength λ2 is
propagates only the optical signal of wavelength λ1 from the direction of arrow 151.
If the optical signal is inputted and taken out as shown by the arrow 152, an optical device having an optical multiplexing and demultiplexing function can be obtained.

FIG. 2 shows another embodiment of the waveguide type optical multiplexer/demultiplexer of the present invention, in which (a) is a side view and (b) is an A-A
It is an ItIr plane view.

In the waveguide-type optical multiplexer/demultiplexer shown in FIG. directional couplers 53 are additionally connected in cascade.

This directional coupler 53 has a characteristic of selectively splitting the optical signal of wavelength λ1 and allowing the optical signal of wavelength λ2 to pass through as is. That is, the optical signal of wavelength λ2 propagating from the direction of arrow 74 is passed as shown by arrow 75. Further, the optical signal of the undesired wavelength λ1 included in the optical signal propagated from the direction of arrow 74 is distributed to the core 34 side, and acts so as not to be outputted in the direction of arrow 75.

FIG. 3 shows an embodiment of the optical multiplexer/demultiplexer module of the present invention. This consists of a waveguide-type optical multiplexer/demultiplexer 16, optical fibers 91 and 92.4', @#, a semiconductor laser paragauge 11 with a built-in laser, a ball lens 10, and a light-receiving element (1 cage) with a built-in light-receiving element. Implemented 12,
This is a so-called bidirectional transmission optical module.

The optical fiber 91 is for bidirectionally propagating optical signals of wavelengths λ1 and λ2, and is composed of a single mode fiber. Optical core inno (92 is a transmission line for guiding the optical signal of wavelength λ2 to the light receiving element package 12,
Single mode fibers can be used with multimode fibers.

The light-receiving element package 12 includes a light-receiving element, a light-receiving element with an interference film filter, or a light-receiving element with 11 lenses added.
Furthermore, it is constructed with a built-in electronic circuit. This light-receiving element balance gauge 12 may be placed directly on the end face of the waveguide IIPI type optical multiplexer/demultiplexer 16 without intervening the optical fiber 92.

The semiconductor laser package 11 is a semiconductor laser that emits an optical signal of wavelength λ1, or a semiconductor laser that emits an optical signal of wavelength λ1.
It is composed of an R lens, a light-receiving element for monitoring an optical signal, a semiconductor laser, and at least one electronic circuit for the light-receiving element.

The ball lens 10 is for efficiently coupling the optical signal of the semiconductor laser into the core 31, and a focusing rod lens, a cylindrical lens, etc. may be used instead of the ball lens.

In the configuration shown in FIG. 3, the semiconductor laser package 11 and the light-receiving element package 12 are placed at positions sufficiently apart from each other, so that the influence of electrical crosstalk between the respective packages can be suppressed to a very small level. . In the figure, if a light receiving element package is used instead of the semiconductor laser package 11, an optical demultiplexer module for separating wavelengths λ1 and λ2 can be constructed. Also,
If a semiconductor laser package that emits an optical signal of wavelength λ2 is used instead of the light receiving element package 12, an optical multiplexer/demultiplexer module can be constructed.

FIG. 4 shows another embodiment of the waveguide type optical multiplexer/demultiplexer of the present invention. This is the wavelength λ1. It demultiplexes the optical signals of λ2 and λ3.

First, this configuration will be explained. The directional coupler 51 separates the optical signals of wavelengths λ2 and λ3, and passes the optical signal of wavelength λ1. The directional coupler 52 has a wavelength λ2
and λ3, and allows the optical signal of wavelength λ1 to pass through. The directional coupler 54 demultiplexes the optical signal of wavelength λ3 and passes the optical signal of wavelength λ2.

The interference film filters 161 and 162 pass an optical signal of wavelength λ1 and reflect optical signals of wavelengths λ2 and λ3. The interference 1-good filter 163 allows the optical signal of wavelength λ2 to pass through and reflects the optical signal of wavelength λ3. The interference film filter 164 allows the optical signal of wavelength λ3 to pass through and reflects the optical signal of wavelength λ2.

Next, the operation of the optical multiplexer/demultiplexer shown in FIG. 4 will be explained.

The wavelength λ1. propagated as indicated by an arrow 171. λ2 and λ3
The optical signal enters the core 31, and the directional coupler 51 separates the optical signals of wavelengths λ2 and λ3 into the core 3211111. The optical signal of wavelength λ1 propagates within the core 31 as it is and is output in the direction of arrow 172. The optical signals of wavelengths λ2 and λ3 propagated in the direction of arrow 173 are demultiplexed in the direction of arrow 174.

Then, in the directional coupler 54, the optical signal of wavelength λ2 is
75 directions, and the optical signal with wavelength λ3 is demultiplexed to the core 34 side. The optical signal of wavelength λ3 branched to the core 34 side is output from the direction of arrow 176 to the direction of arrow 177.

Thus, three wavelengths λ1. λ2. The optical signals of λ3 are demultiplexed.

As can be seen from the configuration of FIG. 4, it is possible to easily multiplex, demultiplex, or combine and demultiplex optical signals of four or more wavelengths. Moreover, even if the positions of the demultiplexed outputs are sufficiently separated, the length D of the waveguide type optical multiplexer/demultiplexer does not increase.

As for the structure of the waveguide, in addition to the buried type shown in this embodiment, a ridge type, a loaded type, and other channel type waveguides can be used.

A light emitting diode may be used instead of a semiconductor laser.

Since the waveguide type optical multiplexer/demultiplexer shown in FIGS. 1, 2, and 4 described above is constructed using a reflecting means such as the reflective film 6 or the interference film filter 162 or 163, the waveguide type optical multiplexer/demultiplexer shown in FIGS. 9
Compared to the configuration shown in the figure, the length of the waveguide (3 cores, 32.33 mm) can be made shorter (total length of about 15 mm), resulting in low loss characteristics.

Furthermore, the reflection means of the waveguide type optical multiplexer/demultiplexer does not necessarily need to be provided at the end of the substrate 1, but as shown in FIG. A membrane 6 may also be provided.

In addition, as shown in FIG. 6, the waveguide end face 1 where light is input and output is
By providing an anti-reflection film on 30, 81, and 82, light reflection due to the difference in refractive index between the end faces may be prevented. Alternatively, the angle of the end surface of the chicken wave path, for example θ
I may be set to an angle smaller than 90'.

When the angle θ1 is set to 90° or less in this way, the distance S between the cores 31 and 33 can be widened, and as a result, the length of the waveguide can be shortened. Here, θ■ is 8
A range of 0'' to 88@ is preferable. In FIG. 7, optical elements (semiconductor laser 77,
This figure shows another embodiment of an optical multiplexer/demultiplexer module in which a light receiving element package 12) and a first fiber 91 are mounted. Since the waveguide end face 81 is set at an angle θ1 of 90″ or less, the optical output from the semiconductor laser 77 is directed to the end face 81.
It will not be reflected back to the semiconductor laser 77 side again. Therefore, the semiconductor laser 77 can perform stable laser oscillation. If an antireflection film is formed on the surface of the interference film filter 6' on the light receiving element package 12 side, reflected light will be less likely to occur from this surface. An anti-reflection coating is also provided on the end surface 83 of the spherical rod lens 10', but it is more preferable to form this end surface 83 at an angle of 90" or less. In addition, in FIG.
If a film is formed that passes the optical signal of wavelength λ1 (wavelength λl) and reflects the optical signal of wavelength λ2, the reflective film 6 becomes unnecessary.

[Effect of the Invention J As described above, according to the present invention, it is possible to realize a compact optical multiplexer/demultiplexer and optical multiplexer/demultiplexer module for wavelength multiplexing transmission with extremely low optical and electrical crosstalk.

Furthermore, low loss characteristics can also be achieved.

[Brief explanation of drawings]

Figures 1, 2 and 6 are diagrams showing embodiments of the optical multiplexer/demultiplexer of the present invention, and Figures 3 and 7 are diagrams showing embodiments of the optical multiplexer/demultiplexer module of the present invention. 4 and 5 respectively show other embodiments of the optical multiplexer/demultiplexer of the present invention, and FIG. 8 schematically shows the wavelength division multiplexing transmission module previously proposed by the present inventor. Figure 9 shows the configuration of the optical multiplexer/demultiplexer previously proposed by the present inventor, and Figure 10 shows the total length of the waveguide and the waveguide spacing when realizing the optical multiplexer/demultiplexer shown in Figure 9. FIG. 2 is a diagram illustrating the relationship between . In the figure, numeral 1 is a substrate, 16 is a waveguide type optical multiplexer/demultiplexer, 2 is a low refractive index, 31 is a core, 32 is a core (waveguide A), 33 is a core (waveguide B), 4 is a cladding layer, 51 is a directional coupler (first wavelength selection element), 52 is a directional coupler, 53 is a directional coupler (second wavelength selection element), 6 is a reflective film, 9
1°92 is an optical fiber, 10 is a ball lens, 10' is a spherical rod lens, 11 is a semiconductor laser package, 1
2 is a photodetector package, 161-164.6' is an interference film filter, 77 is a semiconductor laser, 80.81.82
83 indicates the end face of the waveguide, and 83 indicates the end face of the spherical rod lens. ΣAcknowledgement 4th δ Verbal diagram

Claims (1)

[Claims] 1. In an optical multiplexer/demultiplexer that demultiplexes optical signals with at least two different wavelengths, the first wavelength selection element demultiplexes the optical signals with at least two different wavelengths; By providing another waveguide B in close parallel to the waveguide A through which the waveguide optical signal of at least one wavelength propagates, and by forming reflecting means at the exit end faces of the waveguide A and the waveguide B, An optical multiplexer/demultiplexer characterized in that the demultiplexed optical signal of at least one wavelength is coupled into the waveguide B and propagated in a direction opposite to the propagation direction in the waveguide A. 2. The optical multiplexer/demultiplexer according to claim 1, wherein the reflecting means is a reflective film. 3. The optical multiplexer/demultiplexer according to claim 1, wherein the reflecting means has a function of reflecting only the demultiplexed optical signal of at least one wavelength and passing optical signals of other demultiplexed wavelengths. An optical multiplexer/demultiplexer characterized by being an interference film filter. 4. The optical multiplexer/demultiplexer according to claim 1, wherein the reflecting means is an optical mirror surface obtained by mirror-finishing the exit end surfaces of the waveguides A and B. 5. The optical multiplexer/demultiplexer according to claim 1, wherein a directional coupler is used as the first wavelength selection element. 6. In the optical multiplexer/demultiplexer according to claim 1, on the waveguide B side for guiding the demultiplexed optical signal of at least one wavelength,
Further, a second wavelength selection element is cascade-connected for selectively passing only the demultiplexed optical signal of at least one wavelength and suppressing the other demultiplexed wavelength optical signals. Wave equipment. 7. In the optical multiplexer/demultiplexer according to claim 1, a light-receiving element package or a light-emitting element package is disposed on each of the waveguide terminal sides from which optical signals of at least two different wavelengths are demultiplexed and output. Characteristic optical multiplexer/demultiplexer module. 8. In the optical multiplexer/demultiplexer module according to claim 7, the light-receiving element package includes any one of a single light-receiving element, a light-receiving element with a lens, or a light-receiving element with a built-in electronic circuit, and the light-emitting element package An optical multiplexer/demultiplexer module comprising any one of a single light emitting element, a light emitting element with a lens, or a light emitting element with a built-in electronic circuit. 9. The optical multiplexer/demultiplexer module according to claim 8, wherein an interference film filter is provided in front of the light receiving element of the light receiving element package to pass only an optical signal of a desired wavelength. module. 10. The optical multiplexer/demultiplexer module according to claim 7,
At least one of the light-receiving element packages or light-emitting element packages connected to the waveguide terminal side from which optical signals of at least two different wavelengths are demultiplexed and output is connected via an optical fiber. Optical multiplexer/demultiplexer module. 11. In the optical multiplexer/demultiplexer according to claim 1, another waveguide B is provided close to and parallel to the waveguide A, and a reflection means is formed at the exit end faces of the waveguides A and B. An optical multiplexer/demultiplexer characterized in that at least one optical multiplexer/demultiplexer is further connected in cascade on one side. 12. An optical multiplexer/demultiplexer comprising a combination of at least two optical multiplexer/demultiplexers according to claim 1 to demultiplex optical signals of at least three different wavelengths. 13. In the optical multiplexer/demultiplexer according to claim 12, either a light receiving element package or a light emitting element package is arranged on the waveguide terminal side where optical signals of at least three different wavelengths are demultiplexed and output. An optical multiplexer/demultiplexer module featuring: