JP3342949B2 - Optical module - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention relates to an optical module, and more particularly, high-performance optical modules having excellent light path converting function element and the condensing functional element of the low-cost optical performance compact
Was related to, for example, optical communications are those applied to a optical information processing and optical interconnection.

[0002]

2. Description of the Related Art As a known document describing a conventional optical module having an optical path conversion function element, there is, for example, JP-A-4-208905. The publication discloses a concave portion provided on a semiconductor substrate to obtain an optical semiconductor module that can efficiently optically couple an optical semiconductor element and an optical waveguide element with a small number of parts and a simple process, and that has a small return light. The optical semiconductor element and the optical waveguide element are optically coupled by using the crystal surface exposed on the side surface of the optical waveguide as a reflection surface.

FIGS. 6 (a) and 6 (b) are diagrams showing the construction of an optical module described in the above publication, FIG. 6 (a) is an enlarged view of a reflector, and FIG. 6 (b) is a reflector, a fiber and a PD. FIG. 6 is a diagram illustrating a mounting method with (photodetector). In the figure, 41 is a Si substrate, 42 is an oxide film, 43 and 44 are side surfaces, 45 is a concave portion, 46 is an electrode wiring, 47 is a marker, 48 is a PD (photodetector), 49 is a reflector, and 50 is a fiber connector. , 51 are pins, 52 is a fiber end face, and 53 is an optical fiber.

An oxide film 42 mounted on the surface of a Si substrate 41
When the grooves are formed through an appropriate mask alignment process and anisotropic etching is performed, the side surfaces 43 and 44 serving as reflection surfaces become # 1.
A concave portion 45 with the 11 ° surface exposed is formed. The marker 47 is formed on the surface of the reflector 49 thus formed, and the flip chip is connected with the light receiving surface of the PD 48 facing down. If the necessary electrode wirings 46 are formed on the oxide film 42 on the surface of the reflector 49, the steps up to fixing the PD itself and the wirings are completed in one step.

A fiber connector 50 can be used to connect the reflector 49 and the fiber, and the two fibers are simply connected by abutting the connectors via two pins 51. , So pin 51
The positional relationship between the fiber and the fiber end face 52 is precisely manufactured. Therefore, if the Si substrate 41 is sandwiched between the pins 51 and fixed by an appropriate method, the positional relationship between the fiber end face 52 and the concave portion 45 is also determined precisely. That is, in this module, the optical semiconductor element and the optical waveguide element are optically coupled to each other by using a crystal surface of the concave portion provided in the semiconductor substrate as a reflection surface by a technique such as anisotropic etching.

[0006]

As described above, in the conventional optical module, since the crystal surface is used as the reflection surface, the concave surface is composed of a polyhedron, and the light condensing action involves an aberration such as an aberration. Problems remain in performance. In addition, since an expensive crystal substrate is used, there are problems in mechanical strength and cost.

[0007] The present invention has been made in view of such circumstances, aims to provide a high-performance optical modules having an excellent optical path conversion and condensing function device with low-cost optical performance compact And

[0008]

Means for Solving the Problems The present invention, in order to achieve the above object, and one or more optical waveguide elements even without low, and at least one or more optical elements, at least one optical path conversion function In the optical element having the optical path conversion function, as the optical element having the optical path conversion function, by performing fine processing of a concave portion and adding a reflection function to a curved surface shape, when forming the concave portion, a positioning groove with an optical waveguide element is formed in the concave portion. An integrated parallel substrate, an optical element at a predetermined position, and a parallel substrate provided with at least one groove for positioning an optical waveguide element corresponding to the optical element, wherein the concave portion is formed by an optical path conversion surface. and to act as a light condensing function surfaces is obtained by the features that you have optically coupled to the optical waveguide element and the optical element.

[0009]

According to the present invention, there is provided an optical module comprising at least one or more optical waveguide elements, at least one or more optical elements, and at least one or more optical elements having an optical path conversion function. , and the formed as an optical element having an optical path changing function, performs the addition of fine processing and the reflection function of the recess in the curved shape, when forming the recess, together with positioning grooves of the optical waveguide element in the recess And a parallel substrate provided with an optical element at a predetermined position and at least one groove for positioning an optical waveguide element corresponding to the optical element. A high-performance optical module having an optical element having an optical path conversion and light condensing function that is small, low-cost, and excellent in optical performance because it functions as a functional surface and optically couples the optical waveguide element and the optical element. It is possible to provide.

[0010]

Embodiments will be described below with reference to the drawings. FIG. 1 is a configuration diagram for explaining an embodiment of an optical module according to the present invention, and is a diagram illustrating an optical element having an optical path conversion and a light condensing function. In the figure, 1 is an optical element, 2 is a flat substrate (glass substrate), 3 is an oxide film, 4 is a metal reflection film, and 5 is a concave portion.

In the optical module according to the present invention, fine processing (for example, a photolithography method and a chemical etching method) of the concave portion 5 into a spherical shape or an aspherical shape on the flat substrate 2 as shown in FIG. For example, a metal reflection film 4 is provided), and the concave portion 5 is used as the optical element 1 having an optical path changing surface and a light collecting function surface.

FIGS. 2A and 2B are diagrams showing the construction of an optical module using the optical element shown in FIG. 1. In FIG. 2, reference numeral 6 denotes a semiconductor light receiving element array (light receiving element array substrate), and 6a denotes an optical element. ,
Numeral 7 denotes an optical fiber (optical waveguide element), and other portions having the same functions as those in FIG. 1 are denoted by the same reference numerals.

As shown in FIG. 2, an optical waveguide element 7, for example, an optical fiber, and an optical element 6a, for example, a semiconductor light receiving element, a surface emitting type light emitting diode (LED), a laser diode (LD), etc. The optical element is optically coupled via the concave portion 5 of the optical element, and is realized with high efficiency by utilizing the optical path conversion function and the light collecting function by the concave reflecting mirror.

FIGS. 3 (a) to 3 (e) are views for explaining a method of manufacturing an optical element having an optical path conversion and a light condensing function, wherein 5a is a concave surface, 10 is an opening, and FIGS. Portions having the same function are denoted by the same reference numerals.

In the manufacturing method shown in FIG . 3, a transparent glass substrate 2 is used as the flat substrate 2, and first, a resist pattern is formed on the surface of the substrate by a photolithography technique to provide a circular opening 10 (see FIG. 3). (A)). Using this as a mask, etching is performed with an etching solution such as hydrofluoric acid or buffered hydrofluoric acid, and a spherical concave surface 5a having a curvature radius of about several hundred μm is used.
(FIG. (B)), the resist is peeled off, and then A
After a metal thin film such as l (aluminum) or Ag is formed by a thin film forming method such as a vapor deposition method and a reflection function is added (FIG. (c)), the same applies to a SiO thin film for electrical insulation of the substrate. It is laminated by a method. Then, it is cut into a predetermined shape (FIG. (D)) to obtain the optical element 1 (FIG. (E)).

FIGS. 4 (a) and 4 (b) are views for explaining a method of adding a reflection function of an optical element having an optical path conversion and a light condensing action. In the figures, reference numeral 20 denotes a metal thin film, and 21 denotes a metal film. , 2
Numeral 2 denotes a thin film, and other portions having the same function as in FIG. 3 are denoted by the same reference numerals.

As a method of adding a reflection function to the other concave portion 5a, as shown in FIG. 4A, before forming the metal thin film 20 by the thin film forming technique, the substrate surface excluding the concave surface is formed by photolithography. A resist film is formed, and after forming the metal film, the metal film 21 on the resist film is formed by a lift-off method.
The optical element 1 can be obtained by cutting the substrate, which has been patterned by removing the substrate, into a predetermined shape.

Further, as shown in FIG. 4 (b), a plurality of transparent thin films 22 having different refractive indexes (for example, TiO ₂ or S
It is also possible to use a substrate in which iO ₂ is laminated as a pair so that each layer has an optical thickness of λ / 4 with respect to the wavelength used, and the concave surface 5a has high reflectance and wavelength selectivity. . Further, by controlling the shape of the mask opening 10 when the concave surface 5a is formed, the concave surface 5a can be made aspherical.

FIGS. 5A to 5E are configuration diagrams for explaining another embodiment of the optical module according to the present invention. FIG. 5A is a perspective view of another embodiment, and FIG. Is a still another embodiment, FIG. (C) is a top view of FIG. (B), FIG. (D) is a state diagram in which an optical element and an optical fiber are coupled, and FIG. (E) is a cross-sectional view of FIG. is there. In the figure, 30 is a reference pin, 31 is a fiber array, 32 and 33 are positioning grooves, 34 is an electrode pattern, and 35 and 36 are alignment marks.

In the present embodiment, a plurality of optical fibers 7 and a semiconductor light receiving element array 6 are coupled via the optical element 1 having a concave array arranged corresponding to the fiber interval. It is mounted with a predetermined space between the reference pins 30. In the optical module of the present invention, the width of the optical element 1 is set to be substantially equal to the distance between the reference pins, and the distance between the reference pins 30 on the light receiving element array substrate 6 arranged corresponding to the fiber interval is set. The fiber array 31 and the optical element 1 and the light receiving element array substrate 6 are mounted on the optical element 1 so as to be loaded therein. However, the positional relationship between these elements and the size of the light receiving surface are determined by the radius of curvature of the concave surface, the incident position of the fiber, and the numerical aperture (NA: Numerical Aperture).

In the case of an optical fiber 7 as an optical waveguide element, a positioning groove 33 for an optical fiber is formed on the light receiving element array substrate 6 by photolithography and anisotropic etching in order to facilitate alignment. The optical fiber 7 is fixed to the optical element 1, and the alignment marks 35,
36 can be provided, and alignment can be performed with reference to this mark. Further, an optical waveguide formed of a thin film corresponds to the light receiving element and the light receiving element array substrate 6
In the case where the device is manufactured monolithically, the alignment can be performed by the above-described alignment method, and the device can be mounted.

When manufacturing the optical element, when forming the concave portion, for example, the opening 10 formed on the resist is formed into a track shape, so that the positioning groove 32 for the optical waveguide element 7 is formed on the substrate. By being formed integrally, the concave portion 5 on the optical element 1 is mounted by mounting the plate of the optical element 1 so as to cover the optical waveguide element 7 at the time of mounting.
And the optical axis of the optical waveguide element 7 can be aligned. At this time, for example, when an optical fiber array is used for the optical waveguide element 7, the optical fiber 7, the optical element 1, and the light receiving element array are formed by forming a fiber positioning groove 33 in the light receiving element array substrate 6. The substrate 6 and the substrate 6 can be positioned collectively, and alignment can be made free.

The light receiving element array substrate 6 can be made of a compound semiconductor crystal such as Si crystal, GaAs, or InP.
It is also possible to use an optical semiconductor element such as D. Further, a glass substrate is used as the optical element array substrate 6, and after forming a concave portion in a spherical shape or an aspherical shape by a photolithography method and the fine processing method by chemical etching, a metal thin film is deposited, and this is used as an electrode. A metal mold made by electroforming or a metal mold with a concave surface formed by precision micromachining is manufactured, and either one of these is replicated in the mold with a resin that cures with heat or light, or a resin that cures with heat. By using the injection-molded substrate, it is possible to produce a substrate having a concave surface with good productivity, cut out the device into a predetermined shape by adding the reflection function and insulation measures, and as the optical element It is also possible to use. The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the technical idea disclosed by the embodiments.

[0024]

As apparent from the above description, according to the present invention, one or more optical waveguide elements even without low, and at least one or more optical elements, and at least one or more of the optical path conversion function An optical module having an optical path conversion function. By acting as a functional surface and optically coupling the optical waveguide element and the optical element, a high-performance optical module having an optical element having an optical path conversion and light condensing function that is small, low-cost, and has excellent optical performance. It is possible to provide .

[Brief description of the drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of an optical element used for an optical module according to the present invention.

FIG. 2 is a configuration diagram of an optical module using the optical element in FIG.

FIG. 3 is a diagram for explaining a method for manufacturing an optical element having an optical path conversion and a light condensing action according to the present invention.

FIG. 4 is a diagram for explaining a method of adding a reflection function of an optical element having an optical path conversion and a light condensing action according to the present invention.

FIG. 5 is a configuration diagram for explaining another embodiment of the optical module according to the present invention.

FIG. 6 is a configuration diagram of a conventional optical module.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical element, 2 ... Flat board (glass substrate), 3 ... Oxide film, 4 ... Metal reflective film, 5 ... Depression, 6 ... Semiconductor light receiving element array (Light receiving element array substrate), 6a ... Optical element, 7 ... Light Fiber (optical waveguide element).

Claims (1)

(57) [Claims] 1. An optical element having at least one or more optical waveguide elements, at least one or more optical elements, and at least one or more optical path conversion functions, wherein the optical element having the optical path conversion function has a curved surface shape. A micro-fabrication of a concave portion and the addition of a reflection function are performed on the parallel substrate, and a groove for positioning with an optical waveguide element is formed integrally with the concave portion when the concave portion is formed; an optical element at a predetermined position; A parallel substrate provided with at least one groove for positioning an optical waveguide element corresponding to the element, wherein the concave portion acts as an optical path conversion surface and a light collecting function surface, and the optical waveguide element and the optical element are optically coupled. An optical module characterized by being optically coupled.