JP2001188147A - Optical device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized device which has small loss and high reliability at a low price. SOLUTION: This optical device has a substrate 1, at least one 1st groove 3 which is formed in the substrate 1, an optical fiber 2 which is arranged in the 1st groove 3, and at least one 2nd groove 4 which obliquely crosses the optical fiber 2, and is equipped with an optical member which is inserted into the 2nd groove 4 and has a surface reflecting or diffracting at least part of light propagated in the optical fiber 2. A photodetecting element is arranged where the light reflected or diffracted by the optical member is received.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device capable of receiving or transmitting and receiving an optical signal by connecting to an optical fiber transmission line and a method of manufacturing the same.

[0002]

2. Description of the Related Art Wavelength division multiplexing (WDM)
on Multiplexing), it is possible to increase the transmission capacity of the optical transmission system. Not only that,
Two-way transmission and simultaneous transmission of different types of signals can also be made possible. As described above, wavelength division multiplexing can flexibly respond to service requests in optical transmission systems, and is applicable to various optical transmission systems such as relay transmission systems, subscriber systems, and local transmission systems. It is possible.

In recent years, in particular, an optical subscriber system for transmitting multi-channel video information and data from a center station to ordinary households using optical fibers has been proposed and studied. In these systems, in a general home subscriber terminal, a plurality of light receiving devices for simultaneously receiving different types of wavelength-multiplexed optical signals and a light emitting device for sending a request or data from the home to the center are provided. Required. For example, a device used for this type of purpose is described in a reference (I. Ikushima et al., "High-performance compact o
ptical WDM transceiver module for passive double s
tar subscriber systems, "Journal of Lightwave Tech
nology, vol. 13, No. 3, March 1995.).

FIG. 30 shows a conventional example of a light receiving optical device applicable to bidirectional signal transmission. This device is disclosed in JP-A-6-331837.

In this device, as shown in FIG.
The first optical fiber 2012 and the second optical fiber 2014 are connected in series via a gap (about several μm).
One end of the first optical fiber 2012 is cut obliquely with respect to the optical axis, and a semi-transmissive / semi-reflective surface 2011 for reflecting a part of the optical signal and transmitting the rest is formed in that part. Similarly, one end of the second optical fiber 2014 is also cut obliquely with respect to the optical axis, and a semi-transmissive / semi-reflective surface 2013 that reflects a part of the optical signal and transmits the rest is provided in that part.
Are formed.

The semi-transmissive / semi-reflective surface 201 of the second optical fiber
3 is a semi-transmissive / semi-reflective surface 201 of the first optical fiber 2012
1 and the first and second optical fibers 2012 and 2014 so that they face each other and their optical axes are linear.
Is arranged.

[0007] The optical signal propagating from the right side in the figure is reflected by the semi-transmissive / semi-reflective surface 2011 of the first optical fiber 2012 and is emitted from the optical fiber 2012 to the outside.
A first photodiode 2015 is arranged on the path of the optical signal, and receives the optical signal to generate an electric signal.

[0008] The optical signal propagating from the left side in the figure is reflected by the semi-transmissive / semi-reflective surface 2013 of the second optical fiber 2014 and emitted from the second optical fiber 2014 to the outside. A second photodiode 2 is provided on the optical signal path.
016 is arranged to receive the optical signal and generate an electric signal.

[0009]

In this conventional optical device, a semi-transmissive / semi-reflective surface is formed directly on an end face of an optical fiber cut obliquely. For this purpose, (1) it is necessary to make a special cut so that the end face of the optical fiber becomes smooth, or to perform a polishing process after performing an oblique cut. (2) In order to form a semi-transmissive / semi-reflective surface on the end face of the optical fiber, it is necessary to deposit a thin film on the end face of the optical fiber. The process of inserting an optical fiber into a thin film deposition device such as a vacuum deposition device and depositing a thin film on the end face lowers the production throughput.

In addition, since two different optical fibers are separately obliquely cut and then arranged so that the optical axes are aligned,
(3) It is necessary to adjust the optical axis with high accuracy,
(4) The optical axis shift tends to increase the propagation loss of light between the two optical fibers, and the transmission loss varies between the devices. (5) In the state where the optical axes of the two optical fibers are aligned, even if the gap between the optical fibers is about several μm, there is a difference in the refractive index between the optical fiber and the air. And the transmission loss may be extremely large.

The present invention has been made in view of the above problems, and has a reduced size.
An object of the present invention is to provide a low-cost optical device by improving integration and weight while improving productivity.

Another object of the present invention is to provide a bidirectional optical device which receives or transmits an optical signal by connecting to an optical fiber transmission line, and a method of manufacturing the same.

[0013]

The optical device of the present invention comprises:
An optical device comprising: a substrate; at least one first groove formed in the substrate; an optical fiber disposed in the first groove; and at least one second groove obliquely crossing the optical fiber. And an optical member that is inserted into the second groove and has a surface that reflects or diffracts at least a part of light propagating through the optical fiber.

[0014] In a preferred embodiment, in the second groove, the material having at least the between the optical member and the optical fiber is substantially equal refractive index n _r of the refractive index n _f of a core portion of the optical fiber Is buried.

In a preferred embodiment, between the refractive index n _r and the refractive index n _f , 0.9 ≦ (n _r / n _f ) ≦
1.1.

In a preferred embodiment, the material having the refractive index _nr is formed of a resin.

In a preferred embodiment, the material having the refractive index _nr is formed of an ultraviolet curable resin.

In one embodiment, fine irregularities are present on the inner wall of the second groove.

In one embodiment, the optical member selectively reflects light having a wavelength in a selected range.

In one embodiment, the optical member selectively transmits light having a wavelength in a selected range.

In a preferred embodiment, the optical member includes:
Refractive index n_bA base formed of a material having
A dielectric multilayer film formed on the
Rate n _bAnd the refractive index n_fAnd 0.9 ≦ (n_b/
n_f) ≦ 1.1.

In one embodiment, the surface of the optical member has a diffraction grating.

In one embodiment, the substrate is made of a material transparent to signal light propagating through the optical fiber.

[0024] In one embodiment, the substrate is formed of glass.

In one embodiment, the substrate is formed from a ceramic.

In one embodiment, the substrate is formed from a semiconductor.

In a preferred embodiment, a normal to the surface of the optical member is not parallel to an optical axis of the optical fiber.

In a preferred embodiment, the second groove is inclined with respect to the upper surface of the substrate.

In one embodiment, at least one optical element for receiving light reflected or diffracted by the optical member is provided on the substrate.

In one embodiment, at least one second optical element for receiving light transmitted through the optical member is further provided on the substrate.

In one embodiment, the substrate has a top surface and a bottom surface, and a first light receiving element disposed on the bottom surface of the substrate for receiving light reflected or diffracted by the optical member; A second light receiving element disposed on the upper surface of the substrate and receiving light reflected or diffracted by the optical member.

In one embodiment, the substrate includes an upper surface,
A first light receiving element that has a bottom surface with a reflector attached thereto, is disposed on the upper surface of the substrate, and receives light reflected or diffracted by the optical member, and is disposed on the upper surface of the substrate; A second light receiving element that receives the light reflected or diffracted by the optical member via the reflector.

The substrate has a top surface, a bottom surface, and a plurality of side surfaces, and is disposed on one of the plurality of side surfaces of the substrate.
A first light receiving element for receiving light reflected or diffracted by the optical member, and a second light receiving element disposed on another one of the plurality of side surfaces of the substrate and receiving light reflected or diffracted by the optical member And further provided.

[0034] In one embodiment, the optical element is a light receiving element that generates an electric signal according to the received light.

In a preferred embodiment, the light receiving element is
It is fixed on the substrate.

[0036] In a preferred embodiment, between the substrate and the light-receiving surface of the light receiving element, the material having a refractive index substantially equal to n _p the refractive index n _f of a core portion of the optical fiber is filled.

In one embodiment, a low reflectance film is formed on the light receiving surface of the light receiving element.

In one embodiment, the number of the second grooves is plural, and optical members having different filter characteristics are inserted into each of the plural second grooves.

In one embodiment, the number of the first grooves is plural and the number of the second grooves is singular, and the single second groove crosses the plurality of first grooves.

In one embodiment, the number of the first grooves is plural, and the plurality of first grooves are arranged on the substrate so as to be substantially parallel.

In one embodiment, a third groove is formed on the substrate along a direction intersecting the first groove, and another optical fiber is provided in the third groove. ,
Light reflected or diffracted from the optical member is coupled to the other optical fiber.

In one embodiment, laser light emitted from a semiconductor laser is coupled to the end of the optical fiber.

In one embodiment, the substrate has a concave portion on the upper surface and includes a semiconductor laser disposed in the concave portion of the substrate, and an end of the optical fiber is processed into a lens shape. The light emitted from the semiconductor laser is optically coupled to the optical fiber.

In one embodiment, the end of the optical fiber has a movable portion capable of moving the position of the lens-shaped portion relative to the semiconductor laser element, and The movable portion is fixed in a state where the emitted light is optically coupled to the optical fiber.

In one embodiment, the substrate has a concave portion on the upper surface, and a semiconductor laser disposed in the concave portion of the substrate and optically coupling outgoing light of the semiconductor laser to the optical fiber. Lens.

In one embodiment, a support member for supporting the semiconductor laser and the lens is arranged in a concave portion of the substrate.

In one embodiment, the semiconductor laser placed on the supporting member is placed in a concave portion of the substrate after being sorted by inspection.

In one embodiment, a light receiving element for receiving a part of the laser light from the semiconductor laser is provided on the substrate.

In one embodiment, the optical fiber has a first portion functioning as a single mode fiber in the wavelength band of the signal light propagating through the optical fiber, and a second portion functioning as a multimode fiber in the wavelength band of the signal light. And a connecting portion connecting the first portion and the second portion, and a core diameter of the connecting portion gradually changes from the first portion toward the second portion. are doing.

In one embodiment, the core diameter of the second portion of the optical fiber that functions as the multi-mode fiber is increased by heating a part of the single-mode fiber.

In one embodiment, the other optical fiber in the third groove is formed of a multi-mode fiber, and receives light reflected or diffracted from the optical member via the other optical fiber. A light receiving element is further provided.

In one embodiment, an electric wiring pattern is formed on the substrate, and the light receiving element is connected to the electric wiring pattern.

In one embodiment, a semiconductor electric element for performing signal processing of the light receiving element is connected to the electric wiring pattern.

In one embodiment, an optical connector for connecting to another optical fiber is attached to one end of the optical fiber.

In one embodiment, the semiconductor device further comprises a protective film formed so as to cover the upper surface of the substrate.

In one embodiment, the substrate is housed in a housing having an outlet for the optical fiber and a plurality of terminals for electrically connecting to the outside.

In one embodiment, the semiconductor laser is connected to the support member by a first solder material, and the support member is connected by a second solder material having a melting point higher than the melting point of the first solder material. It is connected on the substrate.

In one embodiment, the substrate is housed in a housing having an outlet for the optical fiber and a plurality of terminals for electrically connecting to the outside, and the substrate is mounted on the second substrate. Third with a melting point lower than the melting point of the solder material
Is connected to the bottom of the box.

Another optical device of the present invention comprises: a substrate; at least one first groove formed in the substrate; an optical fiber disposed in the first groove, for transmitting signal light bidirectionally;
An optical device having at least one second groove obliquely crossing the optical fiber, further comprising at least a part of a bidirectional signal light inserted in the second groove and propagating through the optical fiber. Alternatively, the optical device includes an optical member having a diffracting surface, and two light receiving elements that respectively receive light reflected or diffracted by the optical member out of the bidirectional signal light.

In one embodiment, a second groove having a third groove traversing the optical fiber and having a surface inserted in the third groove for reflecting and removing light of an unnecessary wavelength component propagating through the optical fiber. And a member.

In one embodiment, the second groove is perpendicular to the optical axis of the optical fiber.

In one embodiment, the second groove and the third groove are provided so that the reflected light from the second optical member inserted into the third groove does not enter the two light receiving elements. They are formed at different angles with respect to the optical axis of the fiber.

In a preferred embodiment, a material having a refractive index n _r substantially equal to the refractive index n _f of the core of the optical fiber is provided at least between the optical member and the optical fiber in the second groove. Is buried.

In a preferred embodiment, between the refractive index n _r and the refractive index n _f , 0.9 ≦ (n _r / n _f ) ≦
1.1.

In one embodiment, the material having the refractive index n _r is formed of a resin.

In one embodiment, the material having the refractive index n _r is formed of an ultraviolet curing resin.

In one embodiment, fine irregularities exist on the inner wall of the second groove.

In one embodiment, the optical member selectively reflects light having a wavelength in a selected range.

In one embodiment, the optical member selectively transmits light having a wavelength in a selected range.

In one embodiment, the optical member includes a base formed of a material having a refractive index n _b , and a dielectric multilayer film formed on the base, wherein the refractive index n _b
0.9 ≦ (n _b / n _f ) ≦ _b between _b and the refractive index n _f.
1.1.

In one embodiment, the surface of the optical member has a diffraction grating.

In one embodiment, the substrate is formed of a material transparent to signal light propagating through the optical fiber.

[0073] In one embodiment, the substrate is formed of a glass material.

In one embodiment, the substrate is formed from a plastic material.

In one embodiment, the bidirectional signal light is:
The optical member has a wavelength different from each other, and the optical member includes a base that is transparent and has a refractive index substantially equal to the refractive index of the optical fiber, and two reflection coats formed on two main surfaces of the base. , And the two reflection coats respectively show different reflection characteristics.

In one embodiment, the reflection coat is formed from a metal thin film.

In one embodiment, each of the two reflection coats has a multilayer thin film structure.

In one embodiment, each of the two light receiving elements is mounted in a sealed manner on a can-shaped member, and two recesses are formed in the substrate so as to be fitted with the can-shaped member. Have been.

In one embodiment, the two light receiving elements are connected to an electric wiring pattern formed on the substrate.

In one embodiment, the electric wiring pattern is connected to an electric integrated circuit element that detects an electric signal output from at least one of the two light receiving elements and performs signal processing.

In one embodiment, the optical fiber has a first portion functioning as a single mode fiber in a wavelength band of the signal light propagating through the optical fiber, and a second portion functioning as a multimode fiber in the wavelength band of the signal light. And a connecting portion connecting the first portion and the second portion, and a core diameter of the connecting portion gradually changes from the first portion toward the second portion. are doing.

In one embodiment, the substrate is housed in a housing having an outlet for the optical fiber and a plurality of terminals for electrically connecting to the outside.

In one embodiment, the wavelength of the light propagating in the optical fiber in both directions belongs to the 1.3 μm band and / or the 1.5 μm band, and unnecessary light removed by the second optical member. Wavelength is 0.98 μm band or 1.48 μm
It belongs to the m band.

According to the method of manufacturing an optical device of the present invention, a step of forming a first groove in an upper surface of a substrate, a step of embedding and fixing a part of an optical fiber in the first groove, Forming a second groove that traverses, and inserting and fixing an optical member having a surface that reflects or diffracts at least a portion of light propagating through the optical fiber into the second groove.

In a preferred embodiment, the step of inserting and fixing the optical member in the second groove includes the step of inserting the core of the optical fiber into the second groove at least between the optical member and the optical fiber. Embedding a material having a refractive index n _r approximately equal to the refractive index n _{f of the} part.

In a preferred embodiment, between the refractive index n _r and the refractive index n _f , 0.9 ≦ (n _r / n _f ) ≦
1.1.

In one embodiment, the method further includes the step of arranging at least one light receiving element on the substrate.

In one embodiment, the method further includes the step of arranging at least one light receiving element on the substrate.

In one embodiment, the method further includes the step of arranging at least one light emitting element on the substrate.

In another method of manufacturing an optical device according to the present invention, a step of forming a plurality of first grooves on an upper surface of a substrate and a step of embedding and fixing a part of an optical fiber in each of the plurality of first grooves. Forming a second groove obliquely crossing the plurality of optical fibers, and inserting an optical member having a surface that reflects or diffracts at least a part of light propagating through the optical fiber into the second groove. Fixing.

In a preferred embodiment, the angle between the normal direction of the surface of the optical member and the direction of the optical axis of the optical fiber is not less than 5 degrees and not more than 40 degrees.

An optical device according to the present invention comprises a substrate, at least one first groove formed in the substrate, an optical fiber disposed in the first groove, and a substrate formed by obliquely crossing the optical fiber. And an end face, further comprising: a material having a refractive index substantially the same as the refractive index of the core portion of the optical fiber; An optical member having a surface that reflects or diffracts at least a part of the light that is reflected, and a light receiving element that is disposed on the substrate, and is reflected by the optical member among a part of the light that propagates in the optical fiber. A light receiving element for receiving the light.

[0093] In one embodiment, the light receiving element is arranged on a surface of the substrate on which the first groove is formed.

[0094] In one embodiment, the light receiving element is arranged on a surface of the substrate opposite to a surface on which the first groove is formed.

In one embodiment, the optical system includes a third groove traversing the optical fiber, and a second optical member inserted in the third groove and reflecting light in a specific wavelength range. The member prevents light of the specific wavelength region propagating in the optical fiber from being incident on the light receiving element.

In one embodiment, there is provided an optical member for reflecting light in a specific wavelength region, which is attached to the upper surface of the substrate with a resin material having a refractive index substantially equal to the refractive index of the core of the optical fiber. And the light receiving element is disposed on the optical member.

In one embodiment, a filter having a dielectric multilayer structure is formed on the light receiving surface of the light receiving element.

[0098] In one embodiment, the optical fiber is connected to an optical fiber optical transmission line.

In one embodiment, the optical fiber includes:
A ferrule for connecting to an optical fiber transmission line is formed.

According to another method of manufacturing an optical device of the present invention, there are provided a step of forming a first groove on a substrate, a step of fixing an optical fiber in the first groove, and a step of cutting the optical fiber obliquely. ,
Forming an end surface inclined with respect to the optical axis of the optical fiber on the substrate; and forming an optical member having a surface that reflects or diffracts at least a portion of light propagating through the optical fiber by using a core of the optical fiber. A step of attaching to the inclined end surface with a material having a refractive index substantially the same as the refractive index of the portion, and a step of disposing a light receiving element for receiving light reflected or diffracted by the optical member on the substrate.

As described above, in the optical device of the present invention, the signal light is extracted in an arbitrary direction by embedding the optical fiber in the groove of the substrate and embedding the optical member for reflecting or diffracting the light propagating through the optical fiber. That makes it possible.

Also, by using a resin that matches the refractive index of the semiconductor light-receiving element disposed above the substrate with the light extracted in an arbitrary direction, unnecessary reflection points do not occur, and this optical fiber can be used as a multimode light. The connection becomes even easier when it is a fiber.

The optical member may be formed by embedding a layer having a multilayer structure of a dielectric and a metal with a resin material having substantially the same refractive index as that of an optical fiber on both surfaces of the base, or may be provided with a main surface of a certain optical member. The filter characteristics are improved by embedding a resin material having substantially the same refractive index as that of the optical fiber only on different surfaces.

The light extracted by diffraction is coupled to the semiconductor light receiving element array, or extracted outside using another optical fiber, and only a desired wavelength is demultiplexed from a plurality of optical signals of different wavelengths. It can be easily taken out.

In the multi-mode optical fiber in which the optical fiber is connected to the single-mode fiber, the core diameter of the connecting portion changes gradually and continuously, or the optical fiber is subjected to a heat treatment of the single-mode fiber and the optical fiber to obtain the multi-mode fiber. In this case, the light can be coupled to the single-mode fiber with high efficiency by coupling the light to the multi-mode fiber having the enlarged mode diameter.

When a semiconductor laser is arranged in a concave portion of a substrate and an optical fiber having a lens function is used, light can be easily coupled to the optical fiber. When a part of the embedded optical fiber has a movable part, the degree of coupling of light to the optical fiber can be further increased by adjusting the movable part of the optical fiber after connecting the semiconductor laser to the substrate.

When the semiconductor laser and the lens are arranged on different substrates and the optical fiber is arranged on the substrate in which the optical fiber is embedded, the characteristics of the semiconductor laser can be selected in advance by inspection before use, so that the yield of optical devices can be improved. By setting the imaging spot between the semiconductor laser and the lens to be approximately the same as that of the multimode fiber, light from the semiconductor laser can be coupled to the optical fiber with a loose accuracy of about several μm.

When light is extracted from the substrate by a multi-mode fiber, all the light is taken into the semiconductor light receiving device, thereby enabling reception of analog signals without deterioration in quality.

On the surface of the substrate, an electric wiring pattern for connecting to a semiconductor light emitting / receiving element can be formed. Particularly, in the case of a high frequency signal, impedance matching can be performed with an electric circuit connected to the outside. In addition, if an electric element for performing electric signal processing is integrally formed in addition to the semiconductor light receiving and emitting element, the electrical matching becomes good and the size can be reduced.

By arranging so that signals of different wavelengths are separately extracted from the optical fibers embedded in the substrate by different reflection substrates, it is possible to selectively extract the optical signals transmitted by wavelength multiplexing on a single substrate. it can.

If a plurality of optical fibers are arranged and arranged on a substrate, it can be used for a system in which optical signals are independently transmitted in parallel by a plurality of optical fibers on one substrate.

By covering the surface of the substrate with a resin material after the formation of the device on the substrate is completed, the semiconductor device disposed on the surface of the substrate can be protected from external moisture and atmosphere. This substrate can be directly accommodated in a body having an optical fiber outlet and an electrical connection terminal.

A first solder material between the semiconductor laser and the substrate, a second solder material between the substrate and the substrate, a third solder material for connecting the substrate and the member, and a second solder material having a melting point of the first solder material of the second solder. By setting the melting point of the second solder material higher than that of the third solder material, the element is prevented from moving at the time of each solder connection, and reliability can be secured.

[0114]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical device according to the present invention comprises an optical fiber disposed in a first groove of a substrate and at least one second groove obliquely crossing the optical fiber. And an optical member inserted into the second groove and reflecting or diffracting at least a part of the light propagating through the optical fiber. By the function of the optical member, light propagating through the optical fiber can be received by a light receiving element or the like arranged in-line. As a result, light transmitted through the second groove and the optical member therein can be used, and another optical signal can be introduced into the optical fiber from the end of the optical fiber. As a result, it is possible to provide a compact optical transmission terminal in which the optical fiber and the light receiving element and the light emitting element are integrated in various arrangement relationships.

In particular, when the space between the optical member and the optical fiber in the second groove is filled with a material having a refractive index substantially equal to the refractive index of the core of the optical fiber, minute irregularities are formed on the inner wall of the second groove. Even if there is, the light propagating through the optical fiber,
By the inner wall of the second groove, unnecessary influence of scattering and refraction can be avoided. This makes the formation of the second groove extremely easy, for example, eliminating the need to smooth the inner wall of the second groove by polishing.

Further, according to the present invention, since the second groove is formed after the optical fiber is disposed in the first groove of the substrate, a special optical axis alignment step is not required, and the manufacturing process is extremely simplified. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1) First, a first embodiment of an optical device according to the present invention will be described with reference to FIGS. 1A and 1B. FIG. 1A is a perspective view showing only the uppermost part of the first embodiment of the optical device (light receiving module) of the present embodiment, and FIG. 1B is a cross-sectional view taken along the optical fiber of the optical device.

This optical device is constructed by using a glass substrate (thickness 2 mm, length × width = 5 mm × 3 mm) 1 having a V groove (first groove) 3 having a depth of about 130 μm formed on a flat upper surface. Have been. An optical fiber 2 having an outer diameter of 125 μm is arranged in the V-groove 3, and a parallel groove (second groove) crosses the optical fiber 3 obliquely (with respect to its optical axis).
4 is formed on the upper surface of the glass substrate 1. The parallel groove 4 forms an oblique slit in the optical fiber 2, thereby separating the optical fiber 2 into two spatially separated portions. In the present embodiment, the parallel groove 4 is formed such that the normal set on the inner wall of the parallel groove 4 forms an angle of 30 degrees with the optical axis.

The size of the V-groove 3 is designed so that the optical fiber 2 can be stably held. The depth of the V-groove 3 is preferably such that the optical fiber 2 can be completely contained therein. However, even if the uppermost part of the optical fiber 2 is located slightly higher than the upper surface of the substrate 1, there is a big problem. Absent. Instead of the V-shaped groove 3, a groove having a rectangular or U-shaped cross section in a plane perpendicular to the optical axis may be employed.

The parallel groove 4 has a groove width (a distance between inner walls of the groove or a distance between two separated optical fibers) of about 100 μm.
The groove is preferably about m or less. In the present invention, an optical member is inserted into the parallel groove 4. In the case of this embodiment, a light reflecting substrate (with a thickness of 80 μm) having a filter characteristic of selectively reflecting light in the 1.55 μm band
m) 5 is inserted in the parallel groove 4. The light reflecting substrate 5 includes a quartz substrate serving as a base, and a dielectric multilayer film (filter film) in which a silicon oxide film and a titanium oxide film are alternately laminated on at least one main surface thereof. This provides a filter characteristic that exhibits a high reflectance for light within a specific wavelength range. The light reflecting substrate 5 is provided with the parallel grooves 4
It is not necessary to completely house the light reflecting base 5 in the optical fiber 2, and a part of the light reflecting base 5 may protrude above the upper surface of the substrate 1, and is arranged so as to be able to receive the signal light propagating through the optical fiber 2. It should just be.

In order to stably fix the light reflecting substrate 5 in the parallel groove 4, an ultraviolet curable resin 7 is used. This resin is selected so as to be substantially transparent to light having a wavelength of a signal light (1.55 μm band in this embodiment) at least after curing.

FIG. 2 is a sectional view showing the vicinity of the parallel groove 4 and the base 5 in more detail. The inner wall of the parallel groove 4, more precisely, the end faces of the optical fibers 2 that face each other via the parallel groove 4 obliquely cross the optical axis of the optical fiber 2. Therefore, the refractive index n of the core of the optical fiber is provided inside the parallel groove 4.
_When a material having a refractive index different from _f exists, light propagating through the optical fiber 2 is refracted in the parallel groove 4. Thereby, a propagation loss in the parallel groove 4 may occur.
Further, the inner wall of the parallel groove 4 is damaged (mechanical / chemical damage) by a process of forming the parallel groove such as dicing.
And the inner wall of the parallel groove 4 is often formed with fine irregularities.

Even in these cases, the space between the inner wall of the parallel groove 4 and the light reflecting substrate 5 is filled with a material having a refractive index n _r substantially equal to the refractive index n _f of the core of the optical fiber 2. In this case, the light propagating through the optical fiber 2 is straight, without feeling fine irregularities, and without changing the optical axis.
The light travels between the optical fibers beyond the parallel groove 4. According to experiments, between the refractive index n _r and the refractive index n _f , 0.9 ≦
It has been found that it is preferable to have a relationship of (n _r / n _f ) ≦ 1.1. Hereinafter, unless otherwise specified, all resins mentioned in the present specification have a refractive index satisfying the above inequality.

Referring back to FIG. 1A and FIG. 1B. Substrate 1
1.55 reflected by the light reflecting substrate 5
An InGaAs semiconductor light receiving element 6 for detecting signal light in the μm band is arranged. An electrode 8 for making interconnection between the semiconductor light receiving element 6 and an external circuit is formed on the upper surface of the substrate 1.

An arrow 9 in the figure indicates a path of an optical signal of a wavelength band of 1.55 μm transmitted from the other end of the optical fiber 2. Light having a wavelength greatly shifted from the wavelength of the optical signal is hardly reflected by the light reflecting base 5, so that it passes through the light reflecting base 5 and does not reach the light receiving portion of the semiconductor light receiving element 6.

FIG. 3 shows an example in which a substrate on which a diffraction grating is formed is inserted into the parallel groove 4 as an optical member instead of the light reflecting substrate 5 on which a filter film is formed. The light propagating through the optical fiber 2 is diffracted by this diffraction grating,
A plurality of diffracted lights are formed. Among these, the light receiving section of the light receiving element is arranged at a position where the highest order diffracted light can be received. When a plurality of signal lights having different wavelengths propagate through an optical fiber, the diffraction angles differ according to the wavelengths. For this reason, the light receiving units (for example, the photodiodes PD1 and PD
D2, PD3), each signal light can be detected separately. In order to reduce the size of the light receiving element, it is preferable to provide the plurality of light receiving sections on one semiconductor substrate.

Next, referring to FIGS. 4A to 4C,
The traveling path of the signal light reflected by the base 5 will be described.

As shown in FIG. 4A, in this embodiment, a resin is provided between the optical fiber and the light receiving element. Resin having a refractive index n _r is substantially equal to the refractive index n _f of a core portion of the optical fiber is selected. This resin is provided so as to fill at least the path of the signal light. If the resin does not fill the path of the signal light, refraction or scattering of the signal light occurs, so that the light receiving element cannot receive the signal light efficiently. In such a case, since the optical fiber has a columnar structure, the path of the signal light is complicated by the lens effect.

[0130] As in this embodiment, by substantially equal resin is inserted to the refractive index n _f of a core part of the refractive index n _r is the optical fiber, as shown in FIG. 4B, the signal light is straight The light can enter the light receiving portion of the light receiving element.
FIG. 4C schematically shows how the course of the signal light changes depending on the presence or absence of the resin. When refraction or scattering occurs, the spot size of the signal light on the light receiving unit increases, and the detection sensitivity and response speed of the light receiving element decrease. According to an experiment, it is preferable that a relationship of 0.9 ≦ (n _r / n _f ) ≦ 1.1 is preferable between the refractive index n _r and the refractive index n _f . Note that a material other than the resin may be used as long as the material has the same refractive index.

As described above, according to the arrangement of the present embodiment, the signal light selectively reflected by the light reflecting base 5 is applied to the substrate 1.
Does not penetrate inside. Therefore, the substrate 1 does not necessarily need to be transparent to the signal light. In addition to the glass substrate 1, a ceramic substrate or a semiconductor substrate may be used. When a semiconductor substrate is used, a circuit connected to the light receiving element can be formed on the same semiconductor substrate in advance.

The operation of the optical device shown in FIGS. 1A and 1B will be described below.

An optical signal transmitted through the optical fiber 2 (for example, a laser beam in a 1.55 μm band) is reflected by a light reflecting substrate 5 in a parallel groove 4 formed obliquely to the optical axis of the optical fiber 2. It is reflected obliquely. More specifically, a normal line (e.g., “light reflecting substrate 5
When the angle between the optical axis of the optical fiber 2 and the normal formed on the main surface of the optical fiber 2 is about 30 degrees, the signal is formed so that the angle between the reflected light and the optical axis of the optical fiber 2 is about 60 degrees. Light is reflected. On the other hand, light that does not belong to the 1.55 μm band, for example, 1.
When light having a wavelength shifted from 55 μm by about 0.2 μm or more is transmitted through the optical fiber 2, most of the light is transmitted without being reflected by the light reflecting substrate 5.

In the case of this embodiment, as can be seen from FIG. 1A, a plane including both the normal and the optical axis of the optical fiber is:
The direction of the parallel groove 4 is set so as to be perpendicular to the upper surface of the substrate 1.

By such an arrangement, an optical signal within a desired wavelength range is selectively extracted from the upper surface of the glass substrate 1 to the outside of the substrate. A semiconductor light receiving element 6 for detecting an optical signal is arranged at a position where the extracted optical signal can be received.

By the semiconductor light receiving element 6, 1.55
The optical signal in the μm band is converted into an electric signal, and is extracted from the electrode 8 to the outside. The resin 7 is selected so that the electrode of the semiconductor light receiving element 6 is pressed and fixed to the electrode 8 and at the same time, the refractive index does not cause refraction or scattering of an optical signal extracted from the optical fiber 2.

The surface of the semiconductor light receiving element 6 is preliminarily coated with a low reflectance so as not to reflect an optical signal on the surface of the semiconductor layer (light receiving surface). Therefore, most of the optical signal having a wavelength of 1.55 μm propagating in the optical fiber 2 is taken into the light receiving section of the semiconductor light receiving element 6.

The semiconductor light receiving element 6 used here has a wavelength of 1.
Since an InP semiconductor crystal substrate transparent to an optical signal of 55 μm is used, the incident direction of the optical signal may be on either the crystal growth side or the crystal substrate side.

According to this light receiving optical device, the distance between the light signal emitting point of the optical fiber 2 and the light receiving portion of the semiconductor light receiving element is short (about 60 to 300 μm) and set to a constant value with good reproducibility. it can. For this reason, it is suppressed that the light spreads spatially from the optical signal emission point and reaches a region other than the light receiving portion of the semiconductor light receiving element. As a result, 90% or more of the optical signal having a wavelength of 1.55 μm propagating in the optical fiber 2 is taken into the semiconductor light receiving element 6, and high light receiving efficiency is easily achieved. Moreover, unlike the conventional light receiving semiconductor device, there is no problem such as signal deterioration due to the multiple reflection effect of the optical signal between a plurality of flat surfaces such as the light emitting end surface of the optical fiber, the lens end surface, and the semiconductor light receiving element end surface. Therefore, it can also be used for light reception in an analog optical signal transmission system requiring high signal quality. In addition, since all the components are fixed to the glass substrate 1, there is no problem in that the characteristics change due to displacement due to external vibration or external temperature change, and long-term reliability is also improved. Are better.

Next, a method for manufacturing the optical device for receiving light will be described.

First, the glass substrate 1 was mechanically cut.
V-groove 3 is formed on the upper surface of the substrate. Next, after depositing a conductive thin film on the surface of the glass substrate 1 by, for example, a vacuum deposition method, the conductive thin film was processed into a desired electrode pattern by a photolithography step and an etching step, and thereby patterned. The electrode 8 is formed from a conductive thin film. At this time, at the same time when the electrodes 8 are formed by the above-described steps, a “positioning mark” indicating a position where the parallel groove 4 is to be formed and a position where the light receiving element is to be disposed
Is preferably formed on the glass substrate 1.

Next, the optical fiber 2 is made of V
It is embedded in the groove 3.

After the resin is cured, a parallel groove 4 is formed on the glass substrate 1 at the position indicated by the alignment mark. The formation of the parallel grooves 4 can be easily performed by a cutting device called a wire saw or a dicing saw.

Next, the light reflecting substrate 5 is inserted into the parallel groove 4 together with the resin, and the resin is cured. At this time, it is preferable to set the refractive index of the resin to approximately the same as the refractive index of the core of the optical fiber 2. By setting the refractive index of the resin to be substantially the same as the refractive index of the core of the optical fiber 2, excessive light loss (scattering of an optical signal) due to roughness of the inner wall (cut surface) of the parallel groove 4 can be suppressed. As the resin, an ultraviolet curable resin is preferable. This is because there is no need to perform a heating step for curing.

Next, using the resin 7, the semiconductor light receiving element 6
Is fixed at the position indicated by the alignment mark on the glass substrate 1. The alignment is realized by observing the alignment mark on the glass substrate 1 and the semiconductor light receiving element 6 from above the glass substrate 1 and aligning the positions thereof. For this positioning, if a method is used in which a mark indicating the position of the light receiving section is also formed on the semiconductor light receiving element 6 side in advance, the mutual positioning can be performed with higher accuracy.

When an optical signal is incident from the crystal substrate side of the semiconductor light receiving element 6 described above, I
A mark indicating the position of the light receiving section is formed on the nGaAs crystal growth layer side. For this reason, for example, when the electrodes of the semiconductor light receiving element 6 are formed, the alignment marks can be formed at the same time, and a part of the manufacture of the semiconductor light receiving element 6 is facilitated. When a resin material that is cured by irradiating ultraviolet light from the outside is used as the resin material, the semiconductor light receiving element can be fixed at a predetermined position without requiring a long curing time.

When manufacturing this light receiving device, it is not necessary to adjust the position of each component three-dimensionally while detecting the optical signal from the optical fiber. For this reason, it can be manufactured using a mounting device that performs two-dimensional adjustment, such as is used for mounting technology in the field of silicon integrated circuit device manufacturing. Therefore, it is suitable for mass production in a short time, and low price can be expected.

(Embodiment 2) Next, referring to FIG.
A second embodiment of the light receiving device according to the present invention will be described. FIG. 5 shows that the signal light having the wavelength λ1 = 1.55 μm and the wavelength λ2 =
It is sectional drawing of the light receiving optical device which receives a 1.31 micrometer optical signal. In the following, the same reference numerals are given to the same portions as those described with respect to the above-described embodiment, and detailed description of those portions may be omitted.

As shown in FIG. 5, two parallel grooves (groove width: about 100 μm) are formed in the glass substrate 1 at a predetermined angle with respect to the optical axis of the optical fiber 2.
In this embodiment, the angles formed by the parallel grooves with respect to the optical axis are equal, but may be different from each other.

The optical fiber 2 is fixed with resin in the groove formed on the upper surface of the glass substrate 1 as described in the first embodiment.

Light reflecting substrates 11 and 12 of different types are inserted into the two parallel grooves, respectively. The light reflecting substrate (thickness: 80 μm) 11 has a wavelength λ1 = 1.55.
It has a filter characteristic of reflecting 99% or more of the signal light of μm, and the light reflecting substrate (thickness: 80 μm) 12
It has a filter characteristic of reflecting 99% or more of 1.31 μm signal light. The light reflecting substrate 11 has a wavelength λ2 = 1.
About 95% or more of the signal light of 31 μm is transmitted.

On the glass substrate 1, an InGaAs semiconductor light receiving element 13 is arranged so as to receive the signal light having a wavelength λ1 = 1.55 μm reflected by the light reflecting substrate 11. Further, an InGaAs semiconductor light receiving element 14 is arranged on the glass substrate 1 so as to receive the signal light having the wavelength λ2 = 1.31 μm reflected by the light reflecting base 12. Arrows 15, 16, and 17 indicate optical fiber 2
Shows the path of the signal light transmitted from one end of the signal light.

The operation of the optical device according to the present embodiment is as follows.

The light transmitted through the optical fiber 2 first has at least the wavelength λ1 at the position of the optical signal path 15.
= 1.55 μm and signal light of wavelength λ2 = 1.31 μm. The light reflecting substrate 11 has a wavelength of 1.55
Only the optical signal of μm is selectively reflected, and the reflected light is given to the semiconductor light receiving element 13 (path 16). The semiconductor light receiving element 13 generates an electric signal in response to the received optical signal.

On the other hand, an optical signal having a wavelength of 1.31 μm passes through the light reflecting base 11 and is selectively reflected by the light reflecting base 12. The reflected light is given to the semiconductor light receiving element 14,
The semiconductor light receiving element 14 generates an electric signal in response to the received optical signal.

The resin 7 is selected so that the electrodes of the light receiving elements 13 and 14 are fixed to the electrode 8 by pressure bonding, and at the same time, the refractive index does not reflect the optical signal taken out of the optical fiber 2.

The surfaces of the semiconductor light receiving elements 13 and 14 are coated in advance with a low reflectivity so as not to reflect optical signals on the surface of the semiconductor layer. Is received by the semiconductor light receiving element 13 and an optical signal having a wavelength of 1.31 μm is
4

According to this light receiving device, the distance between the light signal emitting point of the optical fiber 2 and the light receiving portion of the semiconductor light receiving element can be made short (about 60 to 300 μm) and set to a constant value with good reproducibility. . For this reason, it is suppressed that the light spreads spatially from the optical signal emission point and reaches a region other than the light receiving portion of the semiconductor light receiving element. As a result, 90% or more of the 1.55 μm wavelength optical signal propagating through the optical fiber 2 is captured by the semiconductor light receiving element 13, and 80% or more of the 1.31 μm wavelength optical signal is captured by the semiconductor light receiving element 14, which is high. Light receiving efficiency is easily achieved. Moreover, unlike the conventional light receiving semiconductor device, there is no problem such as signal deterioration due to the multiple reflection effect of the optical signal between a plurality of end surfaces such as the light emitting end surface of the optical fiber, the lens end surface, and the semiconductor light receiving element end surface. Therefore, it can also be used for light reception in an analog optical signal transmission system requiring high signal quality. In addition, since all the components are fixed to the glass substrate 1, there is no problem in that the characteristics change due to displacement due to external vibration or external temperature change, and long-term reliability is also improved. Are better. The semiconductor light receiving elements 13 and 14 may be two semiconductor light receiving elements formed on the same semiconductor substrate.

Next, the loss of the optical signal passing through the parallel groove will be described with reference to FIG. FIG. 6 shows a calculation result and an experimental result of the optical loss caused by the gap provided in the single mode fiber. It is assumed that a substance having a refractive index n exists in the gap. The solid line in FIG. 6 indicates a wavelength of 1.31 μm.
, And the dashed line indicates the loss of an optical signal having a wavelength of 1.55 μm. When the refractive index of the gap is n = 1.0, n
Two groups of curves are shown corresponding to the case of = 1.5.

The refractive index of the resin used in this embodiment is 1.
It is about 5. From FIG. 6, it can be seen that when the refractive index n = 1.5, only a slight coupling loss of about 1 dB occurs in a gap having a width of 100 μm. This coupling loss is reduced by reducing the gap between the fibers, and
It can also be reduced by increasing the core diameter of the optical fiber.

When manufacturing this light receiving device, there is no need to adjust the position of each component three-dimensionally while detecting the optical signal from the optical fiber. For this reason, it can be manufactured using a mounting device that performs two-dimensional adjustment, such as is used for mounting technology in the field of silicon integrated circuit device manufacturing. Therefore, it is suitable for mass production in a short time, and low price can be expected.

It is to be noted that the light receiving device of this embodiment may be modified so that three or more types of optical signals having different wavelengths can be detected.

(Embodiment 3) Next, a third embodiment of the device according to the present invention will be described with reference to FIGS. 7A to 7B and FIG.

The device of this embodiment is a device in which a light receiving device for receiving optical signals of two wavelengths as shown in FIG. 5 and an electric amplifier are integrated on a single substrate in a hybrid manner.
FIG. 7A is an equivalent circuit showing a part of the circuit of the device, FIG.
B is a schematic perspective view of the device, and FIG. 7C is a plan view thereof.

As shown in FIG. 7B, the light receiving elements 13 and 14 of FIG. 5 are formed on the substrate 1, and these light receiving elements 13 and 14 are, as described in the second embodiment,
The signal light in the selected wavelength band is detected from the light propagating through the optical fiber 2 embedded in the groove (not shown).

The light receiving element is represented by a photodiode symbol in FIG. 7A. When the light receiving element receives the signal light, the potential at the portion between the photodiode and the resistor changes. The electric amplifier amplifies the potential change and outputs it.

Referring to FIG. 7B. First electrical amplifier 21
Are electrically connected to the first light receiving element 13, and the second electric amplifier 22 is electrically connected to the second light receiving element 14.

The first light receiving element 13 is connected to an electric wiring pattern 25 via a first resistor 23, and the second light receiving element 14 is connected to an electric wiring pattern 2 via a second resistor 24.
5 is connected.

The optical signal having a wavelength of 1.55 μm among the optical signals transmitted by the optical fiber 2 is supplied to the first light receiving element 13.
After being converted into an electric signal by the first electric amplifier 21, the electric signal is input to the first electric amplifier 21 and amplified, and then extracted by an electrode pattern not shown in FIG. 7B. The optical signal having a wavelength of 1.31 μm is not detected by the first light receiving element 13, is converted into an electric signal by the second light receiving element 14, is input to the second electric amplifier 22, and is amplified. The amplified signal is
It is extracted by an electrode pattern not shown in FIG. 7B.

The device shown in FIG. 7B is manufactured as described below.

First, the electrode wiring pattern 25 is formed on the glass substrate 1. The electrode wiring pattern 25 is formed by performing a photolithography step and an etching step after a step of depositing a conductive thin film made of an electrode material on the glass substrate 1. Through these steps, various “alignment marks” can be formed from the conductive thin film while forming the electrode wiring pattern 25. 7C shows an example of an electrode wiring pattern.

Next, a V-groove is formed at a predetermined position on the glass substrate 1 based on a “positioning mark” indicating a position where the V-groove is to be formed, and then the optical fiber 2 is embedded in the V-groove. Then, the optical fiber 2 is fixed with resin. Then, after forming two parallel grooves on the glass substrate 1 based on a “positioning mark” indicating a position where a parallel groove (not shown) is to be formed, the light reflecting bases 11 and 12 are placed in the parallel grooves with resin. Fix with. After that, the terminal electrodes of the light receiving elements 13 and 14 are arranged so as to be connected to a part of the electrode pattern 25, and are fixed on the glass substrate 1 with a resin.

FIG. 8 is a diagram showing a configuration in a state where the device shown in FIG. 7B is mounted in a package. In FIG. 8, FIG.
The light receiving device B is denoted by reference numeral 37. The light receiving device 37 is fixed to the bottom of the package 31 with a conductive resin. Thereafter, one end of each electric connection terminal 33 penetrating through the package 31 and an electrode wiring pattern on the light receiving device 37 are connected by an electric connection wire 35 made of aluminum. The other end of the optical fiber extending from the light receiving device 37 in the package 31 to the outside via the optical fiber outlet 32 is connected to the optical connector 36. The surface of the light receiving device 37 is covered with a protective resin, and the light receiving element is protected from moisture, gas, and the like that enter the package 31 from the outside. Next, after filling the optical fiber take-out portion with a resin to perform an airtight process, the lid portion is attached to the package 31.

In manufacturing this device, it is not necessary to precisely position each component in a direction perpendicular to the plane of FIG. 8, and it is sufficient to perform positioning in a plane parallel to the plane of FIG. Therefore, it can be easily manufactured using a normal mounting device used in the field of mounting semiconductor integrated circuits. Since all the components are fixed to the package 31, they have high reliability against mechanical vibration.

(Embodiment 4) Next, a fourth embodiment of the optical device according to the present invention will be described with reference to FIGS. 9A and 9B. FIG. 9A is a plan view of this embodiment, and FIG. 9B is a sectional view thereof. In this embodiment, a plurality of semiconductor laser elements are arranged on a ceramic substrate 41 having a concave portion, in addition to a plurality of light receiving elements. Therefore, it is possible to transmit and receive signal light while having a compact configuration.

Hereinafter, the configuration of the optical device will be described in detail.

The upper surface of the ceramic substrate 41 is divided into a first area where the semiconductor laser device is arranged and a second area where the light receiving element is formed. The first region corresponds to the bottom surface of the concave portion 43 formed in the ceramic substrate 41. FIG.
As shown in B, there is a step between the first area and the second area, and the height of the first area is, for example, about 60 to 70 μm higher than the height of the second area, It is formed low. The reason why the recess is formed on the upper surface of the substrate is that a light emitting element such as a semiconductor laser element is mounted in the recess. In order to align the position of the light emitting portion of the light emitting element with the optical axis of the optical fiber, the relative height of the bottom surface of the concave portion is adjusted.

In the second region on the upper surface of the ceramic substrate 41, three grooves are formed, and an optical fiber 48 is embedded in each groove. One parallel groove is formed so as to obliquely cross the three optical fibers 48. In this parallel groove, light having a wavelength of 1.55 μm is reflected and a wavelength of 1.31 μm is reflected.
One light reflecting base 41 that transmits m light is inserted. These configurations have basically the same configuration as the above-described embodiment, and a detailed description thereof will be omitted.

A semiconductor laser array 44 for emitting laser light having a wavelength of 1.31 μm is arranged on the first region on the upper surface of the ceramic substrate 41. In this embodiment, the semiconductor laser array 44 formed on the same semiconductor substrate is used. Alternatively, three different types of semiconductor laser elements may be separately arranged on the ceramic substrate 41.

On the second region on the upper surface of the ceramic substrate 41, three semiconductor light receiving elements 45 are arranged in parallel. Each of the semiconductor light receiving elements 45 is disposed directly above the corresponding optical fiber 48, and is fixed by resin. The semiconductor light receiving element 45 receives an optical signal having a wavelength of 1.55 μm reflected by the reflection base 41.

A laser element electrode 47 is formed on the first region on the upper surface of the ceramic substrate 41.
The light receiving element electrode 46 is formed on the second area.

At each end of the optical fiber 48, a lens 49 is formed by polishing the end of the optical fiber 48 so as to have a constant curvature. By this lens 49, the signal light emitted from the semiconductor laser array 44 is efficiently incident on the corresponding optical fiber 48.

Hereinafter, a method for manufacturing the optical device will be described.

First, after a concave portion is formed in a part of the ceramic substrate 41, the light receiving element electrode 46 and the laser element electrode 47 are formed on the substrate 41 by the same method as the above-described electrode wiring pattern forming method. I do. Laser element electrode 47
Is formed on the bottom surface in the concave portion of the substrate 41.

Then, after three V-grooves are formed in the ceramic substrate 41 by the above-described method, an optical fiber is fixed in each V-groove with a resin. Thereafter, one parallel groove is formed so as to cross the three optical fibers. One light reflecting substrate 42 is inserted into the parallel groove and fixed with resin.

Thereafter, the semiconductor light receiving element 45 and the semiconductor laser array 44 are mounted at predetermined positions on the ceramic substrate 41 using a resin or a solder material. At this time, the positions of the semiconductor light receiving element 45 and the semiconductor laser array 44 are respectively set to the electrodes 46 and 4 already formed.
Adjusted to 7.

The lens 4 formed at the tip of the optical fiber 48
9 so as to face the corresponding laser beam emitting portion of the semiconductor laser element array 44.
Is arranged. For this reason, the arrayed laser light can be coupled to each optical fiber array at a time. Further, if the projection distance of the lens 49 to the concave portion is increased, the portion of the optical fiber exposed to the concave portion becomes longer.
Due to the elasticity of the lens, the position of the lens 49 can be easily adjusted with respect to the light emitting area of the semiconductor laser element array 44. Therefore, by moving the movable portion of the optical fiber 49, the degree at which light emitted from the semiconductor laser is optically coupled to the optical fiber 48 by the lens 49 can be adjusted. If the movable part is fixed after such adjustment, the light coupling efficiency can be optimized, and a larger light output can be obtained.

According to such an optical device, 1.55 μm wavelength optical signals transmitted in parallel by an optical fiber array composed of a plurality of optical fibers can be separately received by the semiconductor light receiving element array, and at the same time, the wavelength is 1.31 μm.
Can be transmitted. As a result, a plurality of bidirectional optical signal transmissions can be performed by one device. In addition, if the above-described electric circuit for performing signal processing for each of the light emitting and light receiving element arrangements is provided on the same substrate, a more compact and economical optical device can be obtained more easily.

(Embodiment 5) Next, FIGS. 10A and 10B
A fifth embodiment of the present invention will be described with reference to FIG. FIG.
0A is a plan view of this embodiment, and FIG. 10B is a sectional view thereof. In this embodiment, a light receiving element and a semiconductor laser element are arranged on a glass substrate 51 having a concave portion.

Hereinafter, the details of the configuration will be described.

The upper surface of the glass substrate 51 is divided into a first area where the semiconductor laser device is arranged and a second area where the light receiving element is formed. The first region is a glass substrate 51
Corresponds to the bottom surface of the concave portion 54 formed at the bottom. As shown in FIG. 10B, there is a step between the first region and the second region, and the height of the first region is lower by about 60 to 70 μm than the height of the second region. Is formed.

In the second region on the upper surface of the glass substrate 51,
One groove is formed, and an optical fiber 52 that is changed to a multimode fiber 53 is embedded in the groove at the tip. The core diameter of the single mode fiber 52 is 1
0 μm, and the core diameter of the multimode fiber 53 is 5 μm.
0 μm. At the connection between the two fibers, the core diameter is 1
It changes slowly and continuously from 0 μm to 50 μm. Such a structure can be obtained by heat-treating the connection while pulling the optical fiber at both ends.

One parallel groove (not shown) is formed so as to obliquely cross the optical fiber 52. In this parallel groove, light having a wavelength of 1.55 μm is reflected and a wavelength of 1.31 μm is reflected.
One reflection base (not shown) that transmits m light is inserted.

A semiconductor laser element 56 for emitting a laser beam having a wavelength of 1.31 μm is arranged on the first region on the upper surface of the substrate 51. Semiconductor light-receiving elements (not shown) are arranged on the second region on the upper surface of the glass substrate 51, and receive an optical signal having a wavelength of 1.55 μm reflected by the reflective base.

Note that a laser element electrode 58 is formed on the first region on the upper surface of the glass substrate 51.

The semiconductor laser element 56 is disposed in advance together with the lens 57 on the ceramic substrate 55 using a solder material having a melting point of 230 ° C. By applying a current from the electrode 58, its characteristics are inspected. Is selected. Since the semiconductor laser element 56 having poor characteristics is removed at this stage, it is not necessary to unnecessarily connect the optical fiber to the optical fiber, thereby realizing economical efficiency.

The ceramic substrate 55 on which the semiconductor laser element 56 is disposed has a melting point of 1
The connection is made using an 80 degree solder material. The laser beam emitted from the semiconductor laser element 56 is enlarged by the lens 57 to a spot size of about 50 μm. Therefore, when coupling with the multi-mode optical fiber 53, high coupling efficiency can be obtained with a positional accuracy of several μm. Since the core of the laser light coupled to the multi-mode fiber 53 changes gradually and continuously and is connected to the single-mode fiber 52, the optical power is transmitted almost completely without light loss such as scattering. The loose mounting accuracy of the optical fiber coupling system also greatly contributes to economicalization of the optical device.

(Embodiment 6) Next, FIGS. 11A and 11B
A sixth embodiment of the present invention will be described with reference to FIG. 11A and 11B, 61 is a glass substrate, 62
Is a single mode fiber, 63 is a multimode fiber, 64 is a reflecting substrate having a reflectance of 50% for an optical signal having a wavelength of 1.31 μm, 65 is a semiconductor light receiving device, 66 is a semiconductor light receiving device.
Transmits signal light having a wavelength of 1.31 μm and has a wavelength of 1.55 μm.
This is a reflecting substrate that reflects the signal light of the above.

The signal light having a wavelength of 1.55 μm transmitted from the single mode optical fiber 62 is reflected by the reflection base 66 and taken into the multimode fiber 63. By connecting a semiconductor light receiving element to the other end of the multimode fiber 63 and receiving the optical power of all the multi-modes, a high-quality analog signal can be received even in the multi-mode use. If all the optical powers of the modes in the multi-mode multi-mode fiber are not received, analog signals cannot be satisfactorily received due to generation of modal noise. The signal light having a wavelength of 1.31 μm transmitted from the single-mode optical fiber 62 is reflected by the reflecting base 64 to form the semiconductor light receiving element 6.
5 is received.

(Embodiment 7) Next, FIGS. 12A and 12B
A seventh embodiment of the present invention will be described with reference to FIG. FIG.
2A is a perspective view of the light receiving and emitting device, and FIG. 12B is a sectional view thereof.

12A and 12B, 71 is a glass substrate, 72 is a single mode fiber, 73 is a reflecting substrate wavelength that transmits signal light having a wavelength of 1.31 μm and reflects signal light having a wavelength of 1.55 μm, and 74 is a wavelength. A reflective substrate having a reflectivity of 50% for an optical signal of 1.31 μm, 75
Is a semiconductor light receiving device for receiving a signal light having a wavelength of 1.55 μm, 76 is a semiconductor light receiving device for receiving a signal light having a wavelength of 1.31 μm, and 77 is a semiconductor having a wavelength of 1.31 μm connected to an optical fiber 72 outside the substrate. The laser 78 is a lens whose fiber end is processed to have a predetermined curvature.

The signal light having a wavelength of 1.55 μm is
And is taken into the semiconductor light receiving device 75. The signal light having the wavelength of 1.31 μm is reflected by the reflection base 74 and received by the semiconductor light receiving element 76. Further, the laser light emitted from the semiconductor laser 77 is coupled to the lens-like fiber 78, and 50% of the light is transmitted through the light reflecting base 74, so that an optical signal can be transmitted bidirectionally. Semiconductor laser device 7
7 may be formed on a similar substrate separate from the glass substrate 71 or may be housed in a separate body.

(Eighth Embodiment) Next, an eighth embodiment of the present invention will be described with reference to FIG.

In FIG. 13, reference numeral 81 denotes a silicon semiconductor substrate; 82, a single mode optical fiber;
A semiconductor light receiving element for receiving a signal light of 55 μm; a semiconductor light emitting element for receiving a signal light of 1.31 μm wavelength;
Reference numeral 5 denotes a semiconductor laser having a wavelength of 1.31 μm. In FIG. 13, a light reflecting substrate (not shown) is disposed so as to cross the optical fiber 82 obliquely. The optical fiber 82 is coupled to the light receiving elements 83 and 84 and the light emitting element 85 via the light reflecting base. Here, the light emitting element 85 is a surface emitting laser, and is arranged on the upper surface of the silicon substrate 81 together with the light receiving elements 83 and 84.

This optical device can be manufactured by the same mounting method as that for assembling a normal semiconductor integrated circuit, and is easy to assemble, so that economy can be achieved, and miniaturization and reliability can be achieved. It is excellent.

In the above embodiments, the optical devices having the wavelengths of 1.55 μm and 1.31 μm have been mainly described.
Other wavelength combinations may be used. It goes without saying that the constituent materials and the like shown in the embodiments are not limited.

Embodiment 9 Hereinafter, a ninth embodiment of the present invention will be described with reference to FIG. FIG. 14 is a plan view of the present embodiment.

The top surface and the bottom surface are flat and the side surface is perpendicular to the upper surface.
0 μm) 103 is formed. Glass substrate 101
Is formed of a material substantially transparent to light having a wavelength of 1.55 μm. In this groove 103, a single-mode optical fiber (diameter 200 μm) 102 covered with a transparent film formed of a UV resin is fixed by a resin.

The glass substrate 101 is formed so that the second groove (groove width: about 100 μm) 104 forms a predetermined angle (60 degrees) with the optical axis of the optical fiber 102 and is perpendicular to the upper surface of the substrate 101. Formed inside. In the second groove 104, a light reflecting substrate having a filter characteristic (having a thickness of about 80 μm) is provided.
m) 105 is inserted and fixed by the resin 108. The resin 108 is formed of an epoxy-based material transparent to 1.55 μm light, and has a refractive index substantially equal to the refractive index of the optical fiber. The light reflecting base 105 is designed to selectively reflect only signal light having a wavelength of 1.55 μm at a rate of 10%. Such a light reflecting substrate 1
05 is obtained, for example, by alternately stacking a silicon oxide film and a titanium oxide film on a quartz substrate. In the figure, optical signals propagating in a bidirectional optical fiber having a wavelength of 1.55 μm are indicated by reference numerals 100 and 100 ′, respectively.

The substrate 10 parallel to the optical axis of the optical fiber 102
The first InGaAs semiconductor light receiving element 106 is mounted on one side of the one side, and the second InGaAs semiconductor light receiving element 107 is mounted on the other side.

A part of the optical signal 100 propagating from the left in the figure is reflected by the reflecting base 105 and enters the first semiconductor light receiving element 106 as the first reflected light 109.
The rest of the optical signal 100 passes through the reflective substrate 105 and propagates right through the optical fiber 102. On the other hand, a part of the optical signal 100 ′ propagating from the right side in FIG.
05, and is incident on the second semiconductor light receiving element 107 as the second reflected light 110. The rest of the optical signal 100 ′ passes through the reflective substrate 105 and propagates through the optical fiber 102 to the left.

This device is inserted into the transmission line of an optical fiber, and optical signals 100 and 100 ′ are
2 is transmitted in both directions.

The surfaces of the semiconductor light receiving elements 106 and 107 are previously coated with a low reflectivity coating so as not to reflect optical signals on the surface of the semiconductor layer.
Are transmitted to the semiconductor light receiving elements 106 and 107. The semiconductor light receiving elements 106 and 107 used here have a wavelength of 1.55 μm.
Since an InP semiconductor crystal substrate transparent to the optical signal is used, the incident direction of the optical signal may be on either the crystal growth layer side or the crystal substrate side.

According to this light receiving device, the transmission loss of the optical fiber can be reduced to about 2.0 dB.
Further, since the distance between the light signal emitting point from the optical fiber 102 and the light receiving portion of the semiconductor light receiving element can be set to be constant and close to within several millimeters, the optical signal is spatially spread and the light receiving portion of the semiconductor light receiving element And light receiving efficiency is not reduced. For this reason, 80% or more of the component (reflected light 109) reflected by the reflective substrate 105 in the optical signal having a wavelength of 1.55 μm propagating through the optical fiber 102 is taken into the semiconductor light receiving element 106, and high efficiency can be easily obtained. . Similarly, a component (reflected light 11) of the 1.55 μm wavelength optical signal propagating through the optical fiber 102 reflected by the first base 105.
80% or more of 0) is taken into the semiconductor light receiving element 107 and high efficiency is obtained.

Further, unlike the conventional light receiving optical device, there is no problem such as signal deterioration due to the multiple reflection effect of an optical signal between a plurality of end surfaces such as a light emitting end surface, a lens end surface, and a semiconductor light receiving element end surface of an optical fiber. It can also be used for light reception in an analog optical signal transmission system requiring high signal quality. In addition, since all components are fixed to the glass substrate 101, there is no problem that characteristics change due to external vibration or positional deviation due to external temperature change, and excellent long-term reliability is achieved. I have.

Embodiment 10 Next, a tenth embodiment of the present invention will be described with reference to FIG.

In the following description, the same portions as those already described are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 15, a substrate 2 made of a plastic material transparent to light having a wavelength of 1.55 μm.
01, the depth is 200 μm, as in the previous embodiment.
Thus, a first groove 203 having a rectangular cross section is formed. In this first groove 203, a single mode optical fiber (having a diameter of 90) having a coating film made of a nylon resin is used.
(Diameter of 0 μm) 202 is embedded.

[0219] The second groove 204 is formed in the substrate 201 so as to be inclined with respect to the main surface of the substrate. In this embodiment, the base 205 is inclined by 60 degrees with respect to the optical axis of the optical fiber. The cross section of the second groove 204 is substantially rectangular and the groove width is 50 μm. In the second groove 204, a gold (Au) thin film is formed on a quartz substrate having a thickness of 30 μm.
A light reflecting substrate 205 having a thickness of 0 angstroms and having semi-transmission / semi-reflection characteristics is embedded together with an epoxy resin.

On the upper surface of the transparent substrate 201, a light receiving diameter of 300
A μm InGaAs semiconductor light receiving element 206 is mounted by surface mounting technology. An InGaAs semiconductor light receiving element 2 having a light receiving diameter of 300 μm is provided on the bottom surface of the transparent substrate 201.
07 is arranged in a state of being enclosed in a can package.

A part of the optical signal 100 is reflected by the base 205 and enters the semiconductor light receiving element 206 as reflected light 208. Part of the optical signal 100 ′ is reflected by the base 205 and enters the semiconductor light receiving element 207 as reflected light 209.

This device is inserted into a transmission line of an optical fiber, and optical signals 100 and 100 ′ are transmitted bidirectionally through an optical fiber 202.

The resin embedded in the second groove 204 is selected such that its refractive index does not cause refraction or reflection of an optical signal extracted from the optical fiber 202. The surface of the semiconductor light receiving element 206 is previously coated with a low reflectivity coating so as not to reflect optical signals on the surface of the semiconductor layer, and has a wavelength of 1.55 μm that propagates through the optical fiber 202.
A part of the optical signal m is taken into the semiconductor light receiving element 206. The semiconductor light receiving element 207 used here has a wavelength of 1.55.
Since a transparent InP semiconductor crystal substrate is used for an optical signal of μm, the incident direction of the optical signal may be on either the crystal growth layer side or the crystal substrate side. Also in this embodiment, the same effects as those obtained by the above-described ninth embodiment can be obtained.

Embodiment 11 Next, an eleventh embodiment of the present invention will be described with reference to FIG. In the following description, the same portions as those already described are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 16, on a glass substrate 301 substantially transparent to light having a wavelength of 1.55 μm,
A first groove 303 having a depth of 200 μm and a rectangular cross section is formed. A single mode optical fiber 302 having a diameter of 125 μm is embedded in the first groove 303.

On the upper surface of the glass substrate 301, a second groove 304 is formed obliquely with respect to the upper surface. Second groove 30
No. 4 has a substantially rectangular cross section and a groove width of 20 μm. A 10 μm thick light reflecting substrate 30 having a filter characteristic of reflecting 1.55 μm light at a rate of 10% in which silicon oxide films and titanium oxide films are alternately laminated on a polyimide film.
5 is inserted into the second groove 304.

A glass substrate 301 has a light receiving diameter of 300 μm.
m InGaAs semiconductor light receiving elements 306 and 307 are fixed by surface mounting technology.

On the bottom surface of the glass substrate 301, gold (Au)
A reflector 308 made of a thin film is formed. Optical signal 1
A part of 00 is reflected by the base 305, further reflected by the reflector 308, and enters the semiconductor light receiving element 306 as reflected light 309. Part of the optical signal 100 ′
The light is reflected by the base 305 and enters the semiconductor light receiving element 307 as reflected light 310.

According to this light receiving optical device, the base 30
5 where the reflected light 310 is formed and the semiconductor light receiving element 3
07 with a constant distance from the light receiving section and 100 to 300 μm
Since it can be set to be as short as about m, the optical signal does not spread spatially and reaches other than the light receiving portion of the semiconductor light receiving element 307, and the light receiving efficiency does not decrease. Further, 90% or more of the reflected light 309 from the base 305 is taken into the semiconductor light receiving element 307, and high light-current conversion efficiency can be easily obtained. Moreover,
High signal without problems such as signal degradation due to the multiple reflection effect of optical signals between a plurality of optical element end faces such as a light emitting end face, a lens end face, and a semiconductor light receiving element end face of an optical fiber, which was a problem in conventional optical devices. It can also be used for light reception in analog optical signal transmission systems requiring quality. In addition, since all the components are fixed to the glass substrate 301, there is no problem that the characteristics change due to external vibrations or positional shifts due to external temperature changes, and excellent long-term reliability is achieved. I have. Semiconductor light receiving elements 306 and 30 arranged
Reference numeral 7 may be a semiconductor light receiving element formed on the same semiconductor substrate.

Next, the loss of an optical signal having a wavelength of 1.55 μm passing through the first groove 303 formed across the optical fiber 302 will be described with reference to FIG. FIG.
FIG. 7 shows a calculation result and an experimental result of light loss due to a gap of a single-mode fiber (core radius ω = 5 μm) of a type normally used for optical communication.

In the case where the gap is filled with a resin having a refractive index substantially equal to the refractive index (n = 1.5) of the optical fiber used in this embodiment, the gap is 0.2 μm for the gap of 20 μm. Only a small coupling loss of about 2 dB occurs. This coupling loss can be reduced firstly by reducing the gap between the fibers and secondly by increasing the core diameter of the optical fiber. FIG. 17 shows that the core radius ω = 1
Calculation results for 0 and ω = 15 μm are also shown. It can be seen that even when the gaps have the same size, when the core radius ω increases, the optical loss is greatly reduced.

FIGS. 18A and 18B show a normal optical fiber 401 and an optical fiber 404 with a partially enlarged core diameter, respectively.

As shown in FIG. 18A, a normal optical fiber 401 has a
03. On the other hand, if the second groove is formed so that the core 402 of the optical fiber 404 crosses the portion 405 having a larger diameter than the other portions,
Signal transmission loss due to the gap of the second groove can be reduced.

In the case of manufacturing this light receiving optical device, it is not necessary to adjust the position of each component while detecting the optical signal from the optical fiber at the time of assembling each component. For this reason, such a light receiving device can be manufactured using a mounting device used in the field of silicon integrated circuit mounting technology, so that it is suitable for mass production in a short time and a low price can be expected. It should be noted that it is not necessary to explain that optical signals having different wavelengths can be manufactured using the same method.

Embodiment 12 Next, a twelfth embodiment of the present invention will be described with reference to FIG.

The device of this embodiment has a similar configuration to the device of FIG. 14, and the same portions are denoted by the same reference numerals.
Description is omitted.

A characteristic feature of the apparatus shown in FIG. 19 is that a third groove 601 having a width of 20 μm and a substantially rectangular cross section is formed on the main surface of the glass substrate 101, and 1.48 is formed therein.
The point is that a second reflective base 602 that selectively reflects light of μm is inserted.

By adopting such a configuration,
A bidirectional signal 600 including light having wavelengths of 1.3 μm, 1.48 μm and 1.55 μm is transmitted from an optical fiber 10 from the left in the figure.
2, the light having a wavelength of 1.48 μm is selectively reflected by the second reflecting base 602 and propagated as reflected light 603 in the left direction in the figure. Bidirectional signal 600 '
Includes signal light having wavelengths of 1.3 μm and 1.55 μm.

[0239] Such an apparatus is preferably an optical fiber amplifier (EDFA: Erubium Doped Fiber Amplifier) doped (doped) with erbium as a rare earth element.
Used to connect to. Pumping light having a wavelength of 1.48 μm is used for pumping the optical fiber amplifier. The second base 602 reduces noise components included in the output of the light receiving element 106 in order to prevent the excitation light from entering the light receiving element 106. Thereby, the light receiving element 10
6, 107 can detect only the optical signal component of the 1.55 μm wavelength.

In this apparatus, the light receiving element 106 is used for monitoring the output of the optical fiber amplifier.
Is used for a reflected light monitor that is reflected from the outside and returns to the optical fiber amplifier.

Also in this embodiment, the space between the second base 602 and the side wall of the third groove is filled with a resin having a refractive index substantially equal to the refractive index of the optical fiber. For this reason, since refraction and scattering reflection of the signal light are suppressed, the transmission loss hardly increases. Since the optical member for filtering the excitation light is integrated with the glass substrate 101, a device having high reliability against mechanical vibration is provided.

(Thirteenth Embodiment) Next, a thirteenth embodiment of the present invention will be described with reference to FIG.

In the present embodiment, the embodiment shown in FIG.
The optical device of 1) is integrated on a substrate together with an electric amplifier.

As described above, some of the optical fibers 701 and 701 ′ are embedded in the grooves of the glass substrate 301. An electric wiring pattern 703 is formed on the glass substrate 301 in advance, and light receiving elements 306 and 307 and an electric integrated circuit element 702 having a preamplifier circuit are formed on the glass substrate 301 so as to be connected to the electric wiring pattern 703. Have been.

The glass substrate 301 is fixed to the bottom of the package 705 with a conductive resin. Thereafter, one end of each electrical connection terminal 704 penetrating the package 705 and the electrode wiring pattern 703 on the glass substrate 301 are connected by an electrical connection wire 703 made of aluminum. The optical fiber 701 extends from inside the package 705 to the outside via the optical fiber outlet. Next, a resin is filled in the optical fiber take-out portion to perform an airtight process, and then the lid portion is attached to the package 705.

In the manufacture of this device, it is not necessary to precisely position each component in a direction perpendicular to the plane of the paper of FIG. 20, and it is sufficient to perform positioning in a plane parallel to the plane of the paper. Therefore, it can be easily manufactured using a normal mounting device used in the field of mounting semiconductor integrated circuits. Since all the components are fixed to the package 705,
High reliability against mechanical vibration.

As described above, according to the present invention, it is possible to reduce the size, integration, and weight of an optical device used in a bidirectional optical transmission system by using an optical fiber, and to improve productivity and reduce cost. There is a remarkable effect that can be of great industrial significance.

Embodiment 14 Hereinafter, a fourteenth embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, a first groove 1103 having a rectangular cross section with a width of 150 μm and a depth of 150 μm is formed on the upper surface of the glass substrate 1101. One end of the optical fiber 1102 is embedded in the first groove 1103 and fixed by a transparent epoxy resin material. Glass substrate 1101
Is formed with an inclined end surface 1104 by cutting with a dicing saw. In this embodiment, the end face 110
The normal direction of 4 is formed so as to form an angle of 30 degrees with the optical axis of the optical fiber 1103. For reasons described below,
This angle is set in the range of 5 to 40 degrees.

On the inclined end face 1104, a reflector 1105 is stuck and fixed with resin. Reflector 1
105 is formed by laminating titanium (Ti) and gold (Au) on a quartz substrate. Glass substrate 11
01, an InGaAs semiconductor light receiving element 1106
Is provided. 1.3 micron optical signal 1107
Is reflected by the reflector 1105 and the reflected light 1108
Incident on the semiconductor light receiving element.

Also in this embodiment, the refractive index of the resin is set to be substantially equal to the refractive index of the optical fiber 1102. For this reason, the physical roughness (fine irregularities) due to the cutting of the end face 1104 is equivalent to a state that does not exist optically.
No light signal scattering occurs. The light signal is efficiently converted into an electric signal by the semiconductor light receiving element 1106 arranged in the reflection direction of the light signal.

According to this light receiving optical device, the distance between the optical signal emitting point of the optical fiber 1102 and the light receiving portion of the semiconductor light receiving element 1106 can be set to be constant and as short as about 60 to 300 microns. For this reason, the optical signal does not spread spatially and reaches other than the light receiving portion of the semiconductor light receiving element to reduce the light receiving efficiency, and 90% or more of the 1.3 μm wavelength optical signal propagating through the optical fiber 1102 is the semiconductor. The light is captured by the light receiving element 1106. As a result, high light receiving efficiency can be easily obtained.

Next, FIG. 22 shows the dependence of the return loss on the inclination angle of the end face. The horizontal axis of the graph in FIG.
The angle between the normal line 105 and the optical axis of the optical fiber 1102 is shown, and the vertical axis shows the turn loss (optical reflectance) as seen from the incident side of the optical fiber 1102.

When the angle is equal to or less than 5 degrees, the return light reflected from the surface of the reflector 1105 is returned to the optical fiber 1102. When the angle is 40 degrees or more (when the angle is 45 degrees or more, the configuration is not considered), the reflected light returned from the surface of the semiconductor light receiving element 1106 is fed back to the optical fiber 1102.

When the reflected return light is large, multiple reflections are caused between the reflected light and the reflection end face of the external optical connector, thereby deteriorating the quality of the received light signal. However, in the present invention, since the angle is set in the range of 5 degrees to 40 degrees, as is apparent from FIG. 22, the light emitting end face of the optical fiber, the end face of the lens used in the conventional light receiving element, and the semiconductor light receiving element There is no problem such as signal deterioration due to multiple reflections between a plurality of optical end surfaces such as end surfaces, and it can also be used for light reception in an analog optical signal transmission system requiring high signal quality.

Further, in the embodiment of the present invention, since the optical parts such as lenses are not used, the apparatus is small, and at the same time, since all the constituent elements are fixed to the glass substrate 1101, external vibration and There is no problem that the characteristics change due to a positional shift due to an external temperature change, and the device has excellent long-term reliability.

Next, a method for manufacturing the light receiving device will be described with reference to FIGS. 23A to 23D.

First, as shown in FIG. 23A, a first groove 1103 having a rectangular cross section is formed on the upper surface of a glass substrate 1101 by mechanical cutting. Glass substrate 110
An electrode material is vacuum-deposited on the upper surface of 1 in advance, and a desired electrode pattern is formed by a subsequent photolithography step and etching step. In these steps, at the same time, a “positioning mark (not shown)” indicating the position where the end face 1104 is formed and the position where the light receiving element is arranged is formed on the upper surface of the glass substrate 1101.

Next, as shown in FIG. 23B, the optical fiber 1102 is buried in the first groove 1103 together with the resin material. Thereafter, the resin is cured.

Next, the portion of the glass substrate 1101 indicated by the above “alignment mark”, that is, FIG.
Is cut using a cutting device called a wire saw or a dicing saw. Thus, as shown in FIG. 23C, the substrate end face 1104 is formed at a predetermined angle with respect to the optical axis of the optical fiber 1102.

Next, as shown in FIG.
A light reflecting base 1105 is attached to the base 104 via a resin,
Fix it. Also, using a resin, the semiconductor light receiving element 110
6 is arranged at a predetermined position indicated by the alignment mark.
When a resin material that is cured by irradiating ultraviolet light from the outside is used as the resin material, the semiconductor light receiving element can be fixed at a predetermined position without requiring a long curing time.

This light receiving device does not need to adjust the position while detecting the optical signal from the optical fiber, and uses all the two-dimensional mounting means used for the existing silicon integrated circuit mounting means. Since it can be manufactured, it is suitable for mass production in a short time, and a low price can be expected.

Embodiment 15 Next, a fifteenth embodiment of the present invention will be described with reference to FIG.

Glass substrate 14 transparent to optical signal wavelength
01, a part of the optical fiber 1402 is embedded and fixed with a transparent epoxy resin material in the first groove 1403 having a width of 150 μm and a depth of 150 μm and having a rectangular cross section formed in the optical fiber 1402 and the glass substrate 1401. Have been.

1404 is an end face of the substrate, 1405 is a reflector,
1406 is a semiconductor light receiving element, 1407 is a 1.3 μm optical signal, and 1408 is reflected light, which is the same as that of the embodiment of FIG. After the optical signal 1407 propagates through the optical fiber 1402, it is reflected upward by a reflector 1405 affixed and fixed on the end face 1404 of the substrate, and is reflected upward.
And a semiconductor light receiving element 1406 disposed on the main surface of the substrate through the transparent glass substrate 1401
And is converted into an electric signal. Also in this light receiving device, excellent characteristics as described in the fourteenth embodiment can be obtained.

Embodiment 16 Next, a sixteenth embodiment of the present invention will be described with reference to FIGS. 25, 26A and 26B. In FIG. 25, 1501 is a silicon substrate,
1502 is an optical fiber, 1503 is a first groove having a width of 140 μm, 1504 is a substrate end face, 1505 is a reflector, 150
Reference numeral 6 denotes a slit having a width of 20 μm as a third groove.
At a predetermined angle with respect to the optical axis of the optical fiber within the main surface of the optical fiber. Reference numeral 1507 transmits light having a wavelength of 1.3 μm formed of a dielectric multilayer film on a polyimide film and transmits light having a wavelength of 1.55 μm.
m, a filter that reflects light, 1508, an InGaAs semiconductor light receiving element, 1509, an epoxy resin having a refractive index substantially equal to that of the optical fiber, 1510, 1.3 μm and 1.55 μ wavelength.
An optical signal of m, 1511 is a 1.3 μm reflected light.

In the configuration of the present optical device, a signal of one wavelength can be selectively received from signal light of two wavelengths. The number of wavelengths and the type of wavelength to be selected are determined by the filter 15
Needless to say, the selection can be made by appropriately selecting 07.

Next, details of the light receiving section of the optical device will be described with reference to FIGS. 26A and 26B.

In FIG. 26, reference numeral 1601 denotes a substrate;
2 is a semiconductor light receiving element, 1603 is a semiconductor light receiving element 160
Reference numeral 1604 denotes an electrode of the semiconductor light receiving element 1602, reference numeral 1605 denotes a substrate electrode having a projection made of a gold (Au) material previously formed on the main surface of the substrate 1601, and reference numeral 1606 denotes an epoxy resin.

FIG. 26A shows the positional relationship between the semiconductor light receiving element 1602 and the substrate electrode 1605 before the resin is fixed.
FIG. 26B shows a state in which the semiconductor light receiving element 1602 and the substrate 1601 are bonded and fixed with an epoxy resin 1606, and an excellent connection between the electrode 1604 and the substrate electrode 1605 is obtained.

(Embodiment 17) Next, a seventeenth embodiment will be described with reference to FIG.

In FIG. 27, reference numeral 1701 denotes a wavelength of 1.55 μm obtained by laminating a dielectric multilayer film on a quartz substrate having a thickness of 40 μm.
This filter transmits light and reflects light having a wavelength of 1.3 μm. Note that the same reference numerals are given to the same portions as those already described, and the description will be omitted. The filter 1701 is a semiconductor light receiving element 150
8 is fixed to the substrate 1501 by using the same resin before being fixed to the resin 1509,
The reflected light 1511 is installed so as to pass through the filter 1701 before reaching the light receiving portion of the semiconductor light receiving element 1508. Thereby, a light receiving characteristic having wavelength selectivity similar to that described in the embodiment of the present invention can be obtained. The same effect can be obtained when a filter is formed directly on the light receiving portion of the semiconductor light receiving element.

Embodiment 18 Next, an eighteenth embodiment of the present invention will be described with reference to FIG. In FIG. 28, reference numeral 1801 denotes a substrate; 1802, a ferrule which is a component of a fiber connector; 1803, an optical fiber in the ferrule; 1804, a slit as a second groove;
5 is a reflector, 1806 is a first groove, 1807 is a semiconductor light receiving element, 1808 is an optical signal, and 1809 is reflected light.
The ferrule 1802 is fixed on the substrate 1801, and is connected to an external optical transmission line via a fiber connector formed later. There is an advantage that a fiber connector can be easily formed by connecting the ferrule 1802 in advance. Also, there is an advantage that the long optical fiber is not dragged in the manufacturing process of the optical device, and the handling is easy. Although the description of the other end of the optical fiber is omitted, if similar ferrules are provided, optical connectors are easily formed on both sides, and connection with an external optical fiber transmission line is facilitated.

Next, the manufacturing method of this embodiment will be described with reference to FIGS. 29A to 29E.

As shown in FIG. 29A, the substrate 1801
A plurality of first grooves 1806 are formed in parallel on the upper surface of. Thereafter, as shown in FIG. 29B, a plurality of optical fibers 1803 with ferrules 1802 are respectively embedded and fixed in the corresponding first grooves 1806 using a resin material. Next, as shown in FIG.
The second groove 1804 is formed obliquely (at a predetermined angle) with respect to the upper surface of the substrate 1801 so as to cross the first groove 1.

Next, as shown in FIG. 29D, after one reflection base 1805 is inserted and fixed in the first groove 1804 together with the resin material, each semiconductor light receiving element 1807 is placed on the substrate 1801. Thereafter, as shown in FIG. 29E, each optical device is divided into respective units.

As described above, the manufacturing method is suitable for mass production because the step of forming the first groove 1806 and the second groove 1804 is processed at once for a plurality of optical devices.

(Embodiment 19) A nineteenth embodiment of the present invention will be described with reference to FIGS. 31A and 31B.

In this embodiment, a first substrate 1901 integrated with a light receiving element and the like is mounted on a second substrate 1902 having a step formed on the upper surface to constitute one optical fiber module. A first groove 1903 is formed in the first substrate 1901.
Is formed, and an optical fiber 1904 is fixed therein with a resin. Further, the second groove 1905 and the light reflecting base 1906 inserted therein traverse the optical fiber 1904 diagonally. As in the previous embodiment, the second groove 190
5, the resin is wrapped around the light reflecting substrate 1906, and is located on the upper surface of the first substrate 1901.
The light receiving element 1907 is fixed at a position where the light reflected by the light receiving portion 6 can be received. The refractive index of these resins is substantially equal to the refractive index of the core of the optical fiber.

The first substrate 1901 and the second substrate 1902 are fixed to each other by an adhesive 1910 such as a silver paste as shown in FIG. 31B. Second substrate 19
Numeral 02 is composed of a thick portion and a thin portion, and a V-groove 1908 for supporting and fixing the tip of the optical fiber 1904 is formed on the upper portion of the thick portion. Second
Substrate 1902 can be formed, for example, by partially etching a selected region of a top surface of a silicon substrate.

[0280] The semiconductor laser device 1
After the mounting of the semiconductor laser device 909, a screening test is performed to determine whether the semiconductor laser device 1909 is a non-defective product having predetermined characteristics. Generally, the semiconductor laser element 190
Since the reliability yield of No. 9 is not 100%, defective products of the semiconductor laser element 1909 are excluded by the above screening test. In the screening test, the light receiving element 19
07 and the first substrate 190 to which the optical fiber 1904 is fixed.
1 may be performed before mounting on the second substrate 1902.

The height of the step provided on the second substrate 1902 is
It is adjusted according to the thickness of the first substrate 1901. The thickness of the first substrate 1901 is, for example, 350 μm,
01 of the first groove 1903 (optical fiber 1
(Corresponding to a core diameter of 904) is 70 μm, the step height of the second substrate 1902 is set to about 270 to 290 μm. Thus, as shown in FIG. 31B, the position of the optical axis of the optical fiber and the light emitting position of the semiconductor laser element can be matched. The electrode wiring patterns (not shown) are formed on the substrates 1901 and 1902 as described in the above embodiment.

According to such an optical fiber module, the signal light from the semiconductor laser element 1909 is efficiently incident on the optical fiber 1904, and the optical fiber
The signal light propagating through the signal line 904 can be efficiently received by the light receiving elements 1907 arranged in-line. According to the present embodiment, it is possible to reduce the size and cost of the subscriber terminal of a general household.

[0283]

As described above, the present invention provides an optical device capable of reducing loss, miniaturization, cost reduction, and high reliability, and a method of manufacturing the same. It greatly contributes to the construction of various optical fiber communication systems, such as mobile communication systems and private transmission systems, and has great industrial significance.

[Brief description of the drawings]

FIG. 1A is a perspective view of a first embodiment of the optical device of the present invention.

FIG. 1B is a sectional view along an optical fiber of a first embodiment of the optical device of the present invention.

FIG. 2 is a cross-sectional view showing details of a reflective base and its periphery.

FIG. 3 is a cross-sectional view showing details of another reflection base and its surroundings.

FIG. 4A is a cross-sectional view of an optical fiber and a light receiving element.

FIG. 4B is a longitudinal sectional view of an optical fiber and a light receiving element.

FIG. 4C is a longitudinal sectional view showing refraction of signal light.

FIG. 5 is a sectional view along an optical fiber of a second embodiment of the optical device of the present invention.

FIG. 6 is an explanatory diagram showing the interval dependence of coupling loss between fibers.

FIG. 7A is a circuit diagram of a third embodiment of the optical device of the present invention.

FIG. 7B is a perspective view of a third embodiment of the present invention.

FIG. 7C is a plan view of a third embodiment of the present invention.

FIG. 8 is a configuration diagram of a third embodiment of the present invention packaged.

FIG. 9A is a plan view of a fourth embodiment of the optical device of the present invention.

FIG. 9B is a sectional view along an optical fiber according to a fourth embodiment of the present invention.

FIG. 10A is a plan view of a fifth embodiment of the optical device of the present invention.

FIG. 10B is a sectional view along an optical fiber according to a fifth embodiment of the present invention.

FIG. 11A is a perspective view of a sixth embodiment of the optical device of the present invention.

FIG. 11B is a sectional view of a sixth embodiment of the present invention.

FIG. 12A is a perspective view of a seventh embodiment of the optical device of the present invention.

FIG. 12B is a sectional view of a seventh embodiment of the present invention.

FIG. 13 is a perspective view of an optical device according to an eighth embodiment of the present invention.

FIG. 14 is a plan view of a ninth embodiment of the optical device of the present invention.

FIG. 15 is a sectional view of an optical device according to a tenth embodiment of the present invention;

FIG. 16 is a sectional view of an optical device according to an eleventh embodiment of the present invention.

FIG. 17 is a graph showing optical coupling loss characteristics in optical fibers having different core diameters.

FIG. 18A is a schematic sectional view of a normal optical fiber.

FIG. 18B is a schematic cross-sectional view of an optical fiber having a partially enlarged core diameter.

FIG. 19 is a plan view of a twelfth embodiment of the optical device according to the present invention.

FIG. 20 is a configuration diagram of a thirteenth embodiment of the optical device according to the present invention.

FIG. 21 is a sectional view of an optical device according to a fourteenth embodiment of the present invention.

FIG. 22 is a graph showing the angle dependence of return loss in a fourteenth embodiment of the present invention.

FIG. 23A is a perspective view showing a manufacturing method according to a fourteenth embodiment.

FIG. 23B is a perspective view showing the manufacturing method of the fourteenth embodiment.

FIG. 23C is a perspective view showing the manufacturing method of the fourteenth embodiment.

FIG. 23D is a perspective view showing the manufacturing method of the fourteenth embodiment.

FIG. 24 is a sectional view of a fifteenth embodiment of the optical device according to the present invention;

FIG. 25 is a sectional view of a sixteenth embodiment of the optical device according to the present invention;

FIG. 26A is a configuration diagram of a sixteenth embodiment.

FIG. 26B is a configuration diagram of a sixteenth embodiment.

FIG. 27 is a sectional view of an optical device according to a seventeenth embodiment of the present invention;

FIG. 28 is a sectional view of an eighteenth embodiment of the optical device according to the present invention.

FIG. 29A is a perspective view showing the manufacturing method of the eighteenth embodiment.

FIG. 29B is a perspective view showing the manufacturing method of the eighteenth embodiment.

FIG. 29C is a perspective view showing the manufacturing method of the eighteenth embodiment.

FIG. 29D is a perspective view showing the manufacturing method of the eighteenth embodiment.

FIG. 29E is a perspective view showing the manufacturing method of the eighteenth embodiment.

FIG. 30 is a schematic view showing a conventional optical device.

FIG. 31A is a perspective view of a nineteenth embodiment of the optical device of the present invention.

FIG. 31B is a sectional view of a nineteenth embodiment of the optical device according to the present invention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Motoji Higashimon 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] A substrate having an upper surface; and at least one first substrate formed on the upper surface of the substrate.
An optical device comprising: a groove; an optical fiber disposed in the first groove; and at least one second groove obliquely traversing the optical fiber and being inclined with respect to the upper surface of the substrate. An optical member that is inserted into the second groove and has a surface that reflects or diffracts at least a part of light propagating through the optical fiber; and an optical member that is disposed on the upper surface of the substrate, At least one first optical element for receiving light reflected or diffracted by the first optical element, wherein an active surface of the first optical element faces the upper surface of the substrate; , is at least between the optical member and the optical fiber, and the material are filled with a refractive index substantially equal to n _r of the refractive index n _f of a core portion of the optical fiber, the law of the surface of the optical member Line direction and The angle formed between the optical axis direction of the serial optical fiber is less than or equal to 40 degrees 5 degrees, the optical device.