Method of fabricating optical component including first and second optical waveguide chips having opposed inclined surfaces

What is claimed is:

1. A method of fabricating an optical component, comprising the steps of:

forming a first optical waveguide chip having a first optical waveguide;

forming a second optical waveguide chip having a second optical waveguide and different from said first optical waveguide chip;

processing said first optical waveguide chip to form a first end face thereof at which an end of said first optical waveguide is exposed;

polishing said first optical waveguide chip to an optical finish to incline a second end face thereof at which an opposite end of said first optical waveguide is exposed, to a direction in which light is propagated through said first optical waveguide;

processing said second optical waveguide chip to form a third end face thereof at which an end of said second optical waveguide is exposed;

polishing said second optical waveguide chip to an optical finish to incline a fourth end face thereof at which an opposite end of said second optical waveguide is exposed, to a direction in which light is propagated through said second optical waveguide; and

positioning said first optical waveguide chip and said second optical waveguide chip relative to each other such that said second and fourth end faces extend substantially parallel to each other with a layer interposed therebetween which has a refractive index that is different from the refractive index of at least one of said first and second optical waveguides, said first and second optical waveguides being optically coupled to each other such that a portion of light propagated from said first optical waveguide to said second optical waveguide is reflected out of at least one of the first and second optical waveguide chips by at least one of said second end face of said first optical waveguide chip and said fourth end face of said second optical waveguide chip, the reflected light propagating through a light transmissive portion of at least one of said optical waveguide chips.

2. A method according to claim 1, wherein at least one of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprises the steps of placing an optical fiber in a V groove of a V-shaped cross section or a U groove of a U-shaped cross section which is defined in a substrate and fixing the optical fiber in the V or U groove with the substrate and a cover.

3. A method according to claim 1, wherein both the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprise the steps of placing an optical fiber in a V groove of a V-shaped cross section or a U groove of a U-shaped cross section which is defined in a substrate and fixing the optical fiber in the V or U groove with the substrate and a cover.

4. A method according to claim 1, wherein at least one of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprises the step of diffusing an impurity in a dielectric substrate to form the optical waveguide in said dielectric substrate.

5. A method according to claim 1, wherein both the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprise the step of diffusing an impurity in a dielectric substrate to form the optical waveguide in said dielectric substrate.

6. A method according to claim 5, wherein said step of diffusing an impurity in a dielectric substrate to form the optical waveguide in said dielectric substrate comprises the step of diffusing an impurity into a dielectric substrate made of LiNbO.sub.3, LiTaO.sub.3, glass, or a semiconductor to form the optical waveguide in said dielectric substrate.

7. A method according to claim 1, wherein said layer comprises one of a layer of air, a layer of dielectric, or a layer of metal.

8. A method according to claim 1, wherein said layer comprises one of a layer of dielectric or a layer of metal, and the ends of said first and second optical waveguides which are exposed at said second and fourth end faces are held in direct contact with opposite surfaces, respectively, of said layer and are optically coupled to each other.

9. A method according to claim 1, wherein one of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprises the steps of placing an optical fiber in a V groove of a V-shaped cross section or a U groove of a U-shaped cross section which is defined in a substrate and fixing the optical fiber in the V or U groove with the substrate and a cover, and wherein the other of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprises the step of diffusing an impurity in a dielectric substrate to form the optical waveguide in said dielectric substrate.

10. A method according to claim 1, wherein said step of positioning comprises the steps of defining first and second guide grooves in said first and second optical waveguide chips and positioning said first and second optical waveguide chips with reference to pins intimately held in said first and second guide grooves.

11. A method according to claim 1, wherein both of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprise the steps of placing an optical fiber in a V groove of a V-shaped cross section or a U groove of a U-shaped cross section which is defined in a substrate and fixing the optical fiber in the V or U groove with the substrate and a cover, and wherein said step of positioning comprises the steps of defining first and second guide grooves in said first and second optical waveguide chips and positioning said first and second optical waveguide chips with reference to pins intimately held in said first and second guide grooves.

12. A method according to claim 1, wherein at least one of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprises the steps of placing an optical fiber in a V groove of a V-shaped cross section or a U groove of a U-shaped cross section which is defined in a substrate and fixing the optical fiber in the V or U groove with the substrate and a cover made of a material which passes light propagated through said optical fiber, said method further comprising the step of fixing to said cover a light-detecting element for detecting the light which is reflected out of at least one of the first and second optical waveguide chips by at least one of said second end face and said fourth end face.

13. A method according to claim 1, further comprising the step of providing a light source for introducing light into said second optical waveguide.

14. A method according to claim 13, further comprising the step of providing an optical coupling means for optically coupling the light from said light source to the end of said second optical waveguide which is exposed at said third end face.

15. A method according to claim 1, wherein said step of forming a first optical waveguide chip having a first optical waveguide comprises the step of forming a first optical waveguide having a plurality of parallel optical waveguides, and said step of forming a second optical waveguide chip having a second optical waveguide comprises the step of forming a second optical waveguide having a plurality of parallel optical waveguides.

16. A method according to claims 1, further comprising the step of providing a light-detecting element for detecting the light which is reflected out of at least one of the first and second optical waveguide chips by at least one of said second end face and said fourth end face.

17. A method of fabricating an optical component, comprising the steps of:

forming a first optical waveguide chip having a first optical waveguide;

forming a second optical waveguide chip having a second optical waveguide which has a refractive index different from the refractive index of said first optical waveguide, and different from said first optical waveguide chip;

processing said first optical waveguide chip to form a first end face thereof at which an end of said first optical waveguide is exposed;

polishing said first optical waveguide chip to an optical finish to incline a second end face thereof at which an opposite end of said first optical waveguide is exposed, to a direction in which light is propagated through said first optical waveguide;

processing said second optical waveguide chip to form a third end face thereof at which an end of said second optical waveguide is exposed;

polishing said second optical waveguide chip to an optical finish to incline a fourth end face thereof at which an opposite end of said second optical waveguide is exposed, to a direction in which light is propagated through said second optical waveguide; and

positioning said first optical waveguide chip and said second optical waveguide chip relative to each other such that said second and fourth end faces extend substantially parallel to each other, the ends of said first and second optical waveguides which are exposed at said second and fourth end faces being held in direct contact with each other and being optically coupled to each other such that a portion of light propagated from said first optical waveguide to said second optical waveguide is reflected out of at least one of the first and second optical waveguide chips by at least one of said second end face of said first optical waveguide chip and said fourth end face of said second optical waveguide chip, the reflected light propagating through a light transmissive portion of at least one of said optical waveguide chips.

18. A method according to claim 17, wherein at least one of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprises the steps of placing an optical fiber in a V groove of a V-shaped cross section or a U groove of a U-shaped cross section which is defined in a substrate and fixing the optical fiber in the V or U groove with the substrate and a cover.

19. A method according to claim 17, wherein both of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprise the steps of placing an optical fiber in a V groove of a V-shaped cross section or a U groove of a U-shaped cross section which is defined in a substrate and fixing the optical fiber in the V or U groove with the substrate and a cover.

20. A method according to claim 17, wherein at least one of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprises the step of diffusing an impurity in a dielectric substrate to form the optical waveguide in said dielectric substrate.

21. A method according to claim 20, wherein said step of diffusing an impurity in a dielectric substrate to form the optical waveguide in said dielectric substrate comprises the step of diffusing an impurity into a dielectric substrate made of LiNbO.sub.3, LiTaO.sub.3, glass, or a semiconductor to form the optical waveguide in said dielectric substrate.

22. A method according to claim 17, wherein both of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprise the step of diffusing an impurity in a dielectric substrate to form the optical waveguide in said dielectric substrate.

23. A method according to claim 17, wherein one of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprises the steps of placing an optical fiber in a V groove of a V-shaped cross section or a U groove of a U-shaped cross section which is defined in a substrate and fixing the optical fiber in the V or U groove with the substrate and a cover, and wherein-the other of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprises the step of diffusing an impurity in a dielectric substrate to form the optical waveguide in said dielectric substrate.

24. A method according to claim 17, wherein said step of positioning comprises the steps of defining first and second guide grooves in said first and second optical waveguide chips and positioning said first and second optical waveguide chips with reference to pins intimately held in said first and second guide grooves.

25. A method according to claim 17, wherein at least one of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide comprises the steps of placing an optical fiber in a V groove of a V-shaped cross section or a U groove of a U-shaped cross section which is defined in a substrate and fixing the optical fiber in the V or U groove with the substrate and a cover made of a material which passes light propagated through said optical fiber, said method further comprising the step of fixing to said cover a light-detecting element for detecting the light which is reflected out of at least one of the first and second optical waveguide chips by at least one of said second end face and said fourth end face.

26. A method according to claim 17, further comprising the step of providing a light source for introducing light into said second optical waveguide.

27. A method according to claim 26, further comprising the step of providing an optical coupling means for optically coupling the light from said light source to the end of said second optical waveguide which is exposed at said third end face.

28. A method according to claim 17, wherein said step of forming a first optical waveguide chip having a first optical waveguide comprises the step of forming a first optical waveguide having a plurality of parallel optical waveguides, and said step of forming a second optical waveguide chip having a second optical waveguide comprises the step of forming a second optical waveguide having a plurality of parallel optical waveguides.

29. A method according to claim 17, further comprising the step of providing a light-detecting element for detecting the light which is reflected out of at least one of the first and second optical waveguide chips by at least one of said second end face and said fourth end face.

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BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of fabricating an optical component, and more particularly to a method of fabricating an optical transmission/reception module for use in optical CATV and optical communication fields.

2. Description of the Related Art

As the optical fiber transmission technology advances, various research activities are directed to optical CATV and optical communication systems which utilize the wide-band characteristics of the optical fibers. It is expected that there will be realized a Fiber-To-The-Home (FTTH) system which has optical fibers led to homes for starting various information services in the near future. For realizing a full-fledged FTTH system, it is necessary to reduce the size and cost of optical terminals connected to respective homes.

The FTTH system requires a bidirectional optical transmission mode which needs to be performed by an optical reception/transmission module comprising a light source for emitting an optical signal, a light-detecting element for converting the optical signal into an electric signal, and an optical coupler for transmitting light from the optical source and light to the light-detecting element to optical fibers that are used to transmit light.

FIG. 1 of the accompanying drawings schematically shows a conventional optical reception/transmission module A. As shown in FIG. 1, the optical reception/transmission module A comprises a laser diode 1, a photodiode 2, and an optical coupler 3. The optical coupler 3 comprises two optical fibers 4, 5 fused together. Therefore, it is difficult to reduce the length of the optical coupler 3. The optical coupler 3 and the laser diode 1, and the optical coupler 3 and the photodiode 2 are connected to each other by optical fibers through fused regions 6 thereof. Consequently, the optical reception/transmission module A is relatively long in its entirety. If a plurality of optical reception/transmission modules A are required, then since the individual optical reception/transmission modules A have to be arrayed horizontally or vertically, the space taken up by the optical reception/transmission modules A increases and the cost of the entire system also increases as the number of optical reception/transmission modules A increases.

As described above, inasmuch as the optical coupler 3 is composed of the two optical fibers 4, 5 fused together and the optical reception/transmission module A is made up of three components, i.e., the laser diode 1, the photodiode 2, and the optical coupler 3, the conventional optical reception/transmission module A has been problematic with respect to both the space occupied thereby and the cost thereof. In the case where the optical reception/transmission module A is incorporated in an on-demand access system of CATV, it is necessary to use many optical couplers 3 and optical reception/transmission modules A in a transmission terminal. Therefore, such an on-demand access system with the conventional optical couplers 3 and optical reception/transmission modules A takes up a large space and is expensive.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method of fabricating an optical component such as an optical coupler or an optical reception/transmission module in a manner to reduce the size thereof.

Another object of the present invention is to provide a method of fabricating an optical component such as an optical coupler or an optical reception/transmission module easily in an integrated configuration, so that the optical component can be reduced in size and cost.

According to the present invention, there is provided a method of fabricating an optical component, comprising the steps of:

forming a first optical waveguide chip having a first optical waveguide;

forming a second optical waveguide chip having a second optical waveguide and different from said first optical waveguide chip;

processing said first optical waveguide chip to form a first end face thereof at which an end of said first optical waveguide is exposed;

polishing said first optical waveguide chip to an optical finish to incline a second end face thereof at which an opposite end of said first optical waveguide is exposed, to a direction in which light is propagated through said first optical waveguide;

processing said second optical waveguide chip to form a third end face thereof at which an end of said second optical waveguide is exposed;

polishing said second optical waveguide chip to an optical finish to incline a fourth end face thereof at which an opposite end of said second optical waveguide is exposed, to a direction in which light is propagated through said second optical waveguide; and

positioning said first optical waveguide chip and said second optical waveguide chip relatively to each other such that said second and fourth end faces extend substantially parallel to each other with a layer interposed therebetween which has a refractive index that is different from the refractive index of at least one of said first and second optical waveguides, said first and second optical waveguides are optically coupled to each other, and a portion of light propagated from said first optical waveguide to said second optical waveguide is reflected out of at least one of the first and second optical waveguide chips by at least one of said second end face of said first optical waveguide chip and said fourth end face of said second optical waveguide chip.

According to the above method, the first optical waveguide chip having the first optical waveguide is formed and polished to an optical finish such that the second end face of the first optical waveguide chip where the end of the first optical waveguide is exposed is inclined to the direction of propagation of light through the first optical waveguide, and the second optical waveguide chip having the second optical waveguide and different from the first optical waveguide chip is formed and polished to an optical finish such that the fourth end face of the second optical waveguide chip where the end of the second optical waveguide is exposed is inclined to the direction of propagation of light through the second optical waveguide. The first and second optical waveguides are positioned relatively to each other such that the second and fourth end faces extend substantially parallel to each other with a layer interposed therebetween which has a refractive index that is different from the refractive index of at least one of the first and second optical waveguides. A portion of light propagated from the first optical waveguide to the second optical waveguide is reflected out of at least one of the first and second optical waveguide chips by at least one of the second and fourth end faces of the first and second optical waveguide chips.

According to the present invention, there is also provided a method of fabricating an optical component, comprising the steps of:

forming a first optical waveguide chip having a first optical waveguide;

forming a second optical waveguide chip having a second optical waveguide which has a refractive index different from the refractive index of said first optical waveguide, and different from said first optical waveguide chip;

processing said first optical waveguide chip to form a first end face thereof at which an end of said first optical waveguide is exposed;

polishing said first optical waveguide chip to an optical finish to incline a second end face thereof at which an opposite end of said first optical waveguide is exposed, to a direction in which light is propagated through said first optical waveguide;

processing said second optical waveguide chip to form a third end face thereof at which an end of said second optical waveguide is exposed;

polishing said second optical waveguide chip to an optical finish to incline a fourth end face thereof at which an opposite end of said second optical waveguide is exposed, to a direction in which light is propagated through said second optical waveguide; and

positioning said first optical waveguide chip and said second optical waveguide chip relatively to each other such that said second and fourth end faces extend substantially parallel to each other, the ends of said first and second optical waveguides which are exposed at said second and fourth end faces are held in direct contact with each other and optically coupled to each other, and a portion of light propagated from said first optical waveguide to said second optical waveguide is reflected out of at least one of the first and second optical waveguide chips by at least one of said second end face of said first optical waveguide chip and said fourth end face of said second optical waveguide chip.

According to the above method, the first optical waveguide chip having the first optical waveguide is formed and polished to an optical finish such that the second end face of the first optical waveguide where the end of the first optical waveguide chip is exposed is inclined to the direction of propagation of light through the first optical waveguide, and the second optical waveguide chip having the second optical waveguide whose refractive index differs from that of the first optical waveguide and different from the first optical waveguide chip is formed and polished to an optical finish such that the fourth end face of the second optical waveguide chip where the end of the second optical waveguide is exposed is inclined to the direction of propagation of light through the second optical waveguide. The first and second optical waveguides are positioned relatively to each other such that the second and fourth end faces extend substantially parallel to each other and the exposed ends of the first and second optical waveguides are held in direct contact with each other and optically coupled to each other. A portion of light propagated from the first optical waveguide to the second optical waveguide is reflected out of at least one of the first and second optical waveguide chips by at least one of the second and fourth end faces of the first and second optical waveguide chips.

Therefore, since a portion of light propagated from the first optical waveguide to the second optical waveguide is reflected out of at least one of the first and second optical waveguide chips by at least one of the second and fourth end faces of the first and second optical waveguide chips, the optical component has a length smaller than a conventional optical component which is composed of two optical fibers fused to each other.

The first optical waveguide is disposed in the first optical waveguide chip, and the second optical waveguide chip is disposed in the second optical waveguide chip, and the first and second optical waveguides are optically coupled to each other and light is emitted from the first optical waveguide chip and/or the second optical waveguide chip by the inclined end faces of the first and second optical waveguide chips. If a plurality of light paths are required, then a plurality of first optical waveguides may be disposed in the first optical waveguide chip, and a plurality of second optical waveguides may be disposed in the second optical waveguide chip. As a result, the optical component may easily be fabricated in an integrated configuration, and reduced in size and cost.

In the case where the second optical waveguide whose refractive index differs from that of the first optical waveguide is disposed in the second optical waveguide chip, even though the first and second optical waveguides are positioned relatively to each other such that the exposed ends of the first and second optical waveguides are held in direct contact with each other and optically coupled to each other, a portion of light propagated from the first optical waveguide to the second optical waveguide is reflected out of at least one of the first and second optical waveguide chips. Consequently, the first and second optical waveguide chips can easily be positioned relatively to each other.

At least one or both of the step of forming the first optical waveguide chip having the first optical waveguide and the step of forming the second optical waveguide chip having the second optical waveguide may comprise the steps of placing an optical fiber in a V groove of a V-shaped cross section or a U groove of a U-shaped cross section which is defined in the substrate and fixing the optical fiber in the V or U groove with the substrate and the cover. With such a process, the first optical waveguide and/or the second optical waveguide becomes an optical fiber. Since this optical fiber is of the same material as the optical fiber used for transmission, these optical fibers can easily be spliced to each other with a small optical loss.

If the first optical waveguide and/or the second optical waveguide is formed by a process including the steps of placing an optical fiber in a V groove of a V-shaped cross section or a U groove of a U-shaped cross section which is defined in the substrate and fixing the optical fiber in the V or U groove with the substrate and the cover, then the optical fiber is positioned accurately in the optical waveguide chip. Even though the first optical waveguide and/or the second optical waveguide is an optical fiber, since the cover is disposed over the optical fiber, a light-detecting element for detecting light emitted out of the first optical waveguide and/or the second optical waveguide may be disposed on the cover. Therefore, the light-detecting element may be installed with ease.

At least one or both of the step of forming the first optical waveguide chip having the first optical waveguide and the step of forming the second optical waveguide chip having the second optical waveguide may comprise the step of diffusing an impurity in a dielectric substrate to form an optical waveguide in the dielectric substrate. With such a process, a number of optical waveguides may easily be formed in a substrate, and may easily be fabricated in an integrated configuration. Where the first optical waveguide and/or the second optical waveguide is in the form of an optical waveguide formed by diffusing an impurity in the dielectric substrate, a light-detecting element or the like may easily be placed on the dielectric substrate even without placing a cover on the dielectric substrate.

Preferably, said step of diffusing an impurity in a dielectric substrate to form the optical waveguide in said dielectric substrate comprises the step of diffusing an impurity into a dielectric substrate made of LiNbO.sub.3, LiTaO.sub.3, glass, or a semiconductor to form the optical waveguide in said dielectric substrate.

In the case where the second and fourth end faces extend substantially parallel to each other with a layer interposed therebetween which has a refractive index that is different from the refractive index of at least one of said first and second optical waveguides, the second and fourth end faces preferably extend substantially parallel to each other with a layer of air, a dielectric, or metal interposed therebetween.

If the layer interposed between the second and fourth end faces is an air layer, the layer should preferably have a thickness in the range of from 0.5 to 10 .mu.m. If the thickness of the layer were smaller than 0.5 .mu.m, then a portion of light propagated from said first optical waveguide to said second optical waveguide would not be practically sufficiently reflected by at least one of said second end face of said first optical waveguide chip and said fourth end face of said second optical waveguide chip. If the thickness of the layer were greater than 10 .mu.m, then the intensity of light propagated from said first optical waveguide to said second optical waveguide would be too low.

In the case where the second and fourth end faces extend substantially parallel to each other with a layer interposed therebetween which has a refractive index that is different from the refractive index of at least one of said first and second optical waveguides, the second and fourth end faces preferably extend substantially parallel to each other with a layer of a dielectric or metal interposed therebetween. With the layer of a dielectric or metal being interposed between the second and fourth end faces, the ends of the first and second optical waveguides which are exposed at said second and fourth end faces are held in direct contact with opposite surfaces, respectively, of said layer.

Consequently, the distance between the exposed ends of the first and second optical waveguides is determined highly accurately, and hence it is possible to determine with accuracy an intensity of light which is transmitted from the first optical waveguide to the second optical waveguide and an intensity of light which is emitted out of at least one of the first and second optical waveguide chips.

Since the dielectric or metal layer is interposed between the exposed ends of the first and second optical waveguides, the intensity of light which is transmitted from the first optical waveguide to the second optical waveguide and the intensity of light which is emitted out of at least one of the first and second optical waveguide chips can easily be controlled by selecting a material of the dielectric or metal layer.

One of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide may comprise the steps of placing an optical fiber in a V groove of a V-shaped cross section or a U groove of a U-shaped cross section which is defined in a substrate and fixing the optical fiber in the V or U groove with the substrate and a cover, and the other may comprise the step of diffusing an impurity in a dielectric substrate to form the optical waveguide in said dielectric substrate.

The step of positioning said first optical waveguide chip and said second optical waveguide chip relatively to each other may comprise the steps of defining first and second guide grooves in said first and second optical waveguide chips and positioning said first and second optical waveguide chips with reference to pins intimately held in said first and second guide grooves. Using the first and second guide grooves and the guide pins, it is possible to position the first and second optical waveguides easily with respect to each other.

Both of the step of forming a first optical wave- guide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide may comprise the steps of placing an optical fiber in a V groove of a V-shaped cross section or a U groove of a U-shaped cross section which is defined in a substrate and fixing the optical fiber in the V or U groove with the substrate and a cover, and the step of positioning said first optical waveguide chip and said second optical waveguide chip relatively to each other may comprise the steps of defining first and second guide grooves in said first and second optical waveguide chips and positioning said first and second optical waveguide chips with reference to pins intimately held in said first and second guide grooves.

The method according to the present invention may further comprise the step of providing a light-detecting element for detecting the light which is reflected out of at least one of the first and second optical waveguide chips by at least one of said second end face and said fourth end face.

If the light-detecting element is employed, at least one of the step of forming a first optical waveguide chip having a first optical waveguide and the step of forming a second optical waveguide chip having a second optical waveguide should preferably comprise the steps of placing an optical fiber in a V groove of a V-shaped cross section or a U groove of a U-shaped cross section which is defined in a substrate and fixing the optical fiber in the V or U groove with the substrate and a cover made of a material which passes light propagated through said optical fiber, and the light-detecting element is fixed to the cover.

The method according to the present invention may further comprise the step of providing a light source for introducing light into said second optical waveguide.

The method according to the present invention may further comprise the step of providing an optical coupling means for optically coupling the light from said light source to the end of said second optical waveguide which is exposed at said third end face.

The step of forming a first optical waveguide chip having a first optical waveguide may comprise the step of forming a first optical waveguide having a plurality of parallel optical waveguides, and said step of forming a second optical waveguide chip having a second optical waveguide may comprise the step of forming a second optical waveguide having a plurality of parallel optical waveguides. With these steps, a highly integrated optical component may be produced.

The angle formed between the second end face of the first optical waveguide and the direction of propagation of light through the first optical waveguide, and the angle formed between the fourth end face of the second optical waveguide and the direction of propagation of light through the second optical waveguide should preferably be 80.degree. or less. If these angles were greater than 80.degree., then the angle of reflection would be too small, and the distance between the reflecting surfaces and the light-detecting element would be too large, resulting in a widely spread light beam and a reduced intensity of detected light.

The angle formed between the second end face of the first optical waveguide and the direction of propagation of light through the first optical waveguide, and the angle formed between the fourth end face of the second optical waveguide and the direction of propagation of light through the second optical waveguide should more preferably be the Brewster's angle or less. The angle of incidence ranging between the Brewster's angle and the critical angle allows the reflectivity to be large.

However, the angle formed between the second end face of the first optical waveguide and the direction of propagation of light through the first optical waveguide, and the angle formed between the fourth end face of the second optical waveguide and the direction of propagation of light through the second optical waveguide should be (90.degree.-- critical angle) or more.

The above and other objects, features, and advantages of the present invention will become apparent from the following description when taken in conjunction with the accompanying drawings which illustrate preferred embodiments of the present invention by way of example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a conventional optical reception/transmission module;

FIG. 2 is a perspective view illustrating a method of fabricating an optical component according to a first embodiment of the present invention;

FIG. 3 is a cross-sectional view illustrating the method of fabricating an optical component according to the first embodiment of the present invention;

FIG. 4 is a side elevational view illustrating the method of fabricating an optical component according to the first embodiment of the present invention;

FIG. 5 is a perspective view illustrating a method of fabricating an optical component according to a second embodiment of the present invention;

FIG. 6 is a cross-sectional view illustrating the method of fabricating an optical component according to the second embodiment of the present invention;

FIG. 7 is a perspective view illustrating a method of fabricating an optical component according to a third embodiment of the present invention;

FIG. 8 is a cross-sectional view illustrating the methods of fabricating an optical component according to the first and second embodiments of the present invention;

FIG. 9 is a cross-sectional view illustrating a method of fabricating an optical component according to a fourth embodiment of the present invention;

FIG. 10 is a cross-sectional view illustrating a method of fabricating an optical component according to a fifth embodiment of the present invention;

FIG. 11 is a cross-sectional view illustrating a method of fabricating an optical component according to a sixth embodiment of the present invention;

FIG. 12 is a cross-sectional view illustrating a method of fabricating an optical component according to a seventh embodiment of the present invention;

FIG. 13 is a cross-sectional view illustrating a method of fabricating a