JPH07168065A - Optical semiconductor module - Google Patents

Abstract

PURPOSE:To actualize such an optical semiconductor module that is available in an E/O converter in an optical fiber communication and excellent in coupling efficiency. CONSTITUTION:A lens holder 13 clamped with a lens 12 is attached to an element holder 11, and also a semiconductor laser 10 is concentrically attached to it. In addition, a ferrule 16 held with an optical fiber 17 is inserted into a cylindrical part 15b of a receptacle 15. A flange part 15a is installed in this receptacle 15, forming a joining surface there. In succession, one side of connecting rings 14 is made contact with the flange part 15a, and the other side is inserted into a cylindrical part 11b of the element holder 11. Next, the semiconductor laser 10 is radiated, and thereby a contact surface to the flange part 15a of the connecting rings 14 and an inserted value to the cylindrical part 11b both are varied to some extent, seeking a position where a quantity of light entering into the optical fiber 17 becomes maximized. Subsequently each of arrows P1 to P4 is welded by a YAG laser beam, and thus every component is clamped tight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical semiconductor module in which light is emitted from a semiconductor light emitting element into an optical fiber.

[0002]

2. Description of the Related Art In an optical semiconductor module used for optical communication using an optical fiber, it is required to efficiently couple light emitted from a semiconductor light emitting element to the optical fiber. A conventional optical semiconductor module will be described with reference to FIG. FIG. 7 is a vertical sectional view showing a configuration example of a conventional optical semiconductor module.

In this figure, a semiconductor laser 1 is attached to a receptacle 2. In the semiconductor laser 1, a mount 1b is joined on a stem 1a, and a laser chip 1d is attached to a side surface of the mount 1b via a silicon submount 1c. The laser chip 1d is a chip that oscillates coherent light (laser light) from its junction when driven by a current, and the laser light is emitted in a direction perpendicular to the stem 1a. A protective cap 1e is joined to the stem 1a to protect the laser chip 1d from the outside air. An opening is provided in the center of the head of the protective cap 1e, and the lens 1
f is fixed. The lens 1f is a lens that converges the laser light emitted from the laser chip 1d, and for example, a small diameter lens of 1 mmφ is used.

The receptacle 2 holds the semiconductor laser 1 coaxially and makes the laser light incident on the optical fiber 3. The receptacle 2 heats the laser chip 1d to the stem 1
It also has a function of radiating heat through a and is made of metal.
The receptacle 2 is integrally formed with a cylindrical portion 2a for holding the semiconductor laser 1, a flange portion 2b for fixing the receptacle 2 itself to the outside, and a coupling portion 2c for coupling with the optical fiber 3. is there. A cylindrical hole is cut out along the central axis of the coupling portion 2c, and the ferrule 4 is inserted therein. Further, a male screw is formed on the outer peripheral surface of the coupling portion 2c, an annular cutout groove is provided between the hole of the central axis and the outer peripheral surface, and the frame 5 is inserted.

The ferrule 4 holds the end of the optical fiber 3 coaxially, and has the function of aligning the end face of the core of the optical fiber 3 with the optical axis of the semiconductor laser 1. The ferrule 4 has a collar portion, and is held by the frame 5 via this collar portion. The outer peripheral portion of the frame 5 is held by a tightening nut 6, and the female thread formed on the inner surface of the tightening nut 6 and the male thread of the receptacle 2 are meshed with each other to allow the optical fiber 3
Are joined in place.

A brief description will be given of an assembling method and an operation of the conventional optical semiconductor module configured as described above.
First, in the semiconductor laser 1, the laser chip 1d is bonded to the side surface of the submount 1c, and the submount 1c is mounted on the mount 1b.
It is attached to the stem 1a via. Next, laser chip 1
In order to protect d from the outside air and to collect the laser light emitted from the laser chip 1d, a protective cap 1e with a lens 1f is put on the stem 1a and welded.

Next, the optical fiber 3 is inserted and fixed in the hole of the ferrule 4, and the tip is mirror-polished. Then, the ferrule 4 is inserted into the receptacle 2. In order to facilitate the insertion / removal of the ferrule 4 into / from the receptacle 2, the tightening nut 6 on the outside of the ferrule 4 is rotated to rotate the ferrule 4
Is fixed to the receptacle 2. When pulling out the ferrule 4, if the tightening nut 6 is loosened and the frame 5 is pulled, the ferrule 4 can be pulled out easily.

The semiconductor laser 1 provided with the lens 1f is finely moved in a direction perpendicular to the central axis with respect to the receptacle 2 to adjust the position, and the cylindrical portion 2a of the receptacle 2 and the stem 1a of the semiconductor laser 1 are soldered. Fix it. In the optical semiconductor module thus assembled, the laser light emitted from the laser chip 1d is condensed by the lens 1f and is incident on the optical fiber 8. An optical semiconductor module having such a structure is disclosed in, for example, Japanese Patent Application Laid-Open No. 1-52103.

[0009]

However, in the above structure, the small lens 1f having a diameter of about 1 mm is used to collect the laser light emitted from the laser chip 1d. Therefore, the aperture angle viewed from the laser chip 1d is small, and the lens 1f can focus only a part of the light emitted from the laser chip 1d. Therefore, there is a drawback that the light coupling efficiency when transmitting the multimode light through the optical fiber 8 having the core diameter of 50 μm is as small as about 20%. Further, in order to facilitate the position adjustment of the semiconductor laser 1, after adjusting the positions so that the central axes of the lens 1f and the laser chip 1d are aligned, the protective cap 1e is attached to the stem 1 of the semiconductor laser 1.
It had a problem that it had to be fixed to a.

The present invention has been made in view of the above problems, and a semiconductor laser and an optical fiber are coupled to each other to improve light coupling efficiency and facilitate position adjustment of a coupling component. The purpose is to realize a semiconductor module.

[0011]

According to a first aspect of the present invention, a converging lens is inserted and fixed in a cylindrical lens holder, a semiconductor laser mounted coaxially with the optical axis of the lens, and a lens holder. Element holder that holds the semiconductor laser and the semiconductor laser coaxially, a cylindrical portion that is slidable in the axial direction into which the element holder is inserted, and a joint portion that has a joint surface perpendicular to the central axis at one end of the cylindrical portion A connecting ring formed with a connecting ring, a flange portion that joins the joining surface of the connecting ring, and a cylindrical portion that is formed coaxially with the flange portion; and an optical fiber that is removably attached to the cylindrical portion of the receptacle. And a ferrule for holding the same coaxially, sliding the cylindrical portion of the connecting ring and the outer peripheral surface cylindrical portion of the element holder in the axial direction, and sliding the receptacle and the connecting ring in a plane perpendicular to the axial direction. Na Caused to emit light Luo semiconductor laser, it is characterized in that each fixed in position to be incident on the optical fiber.

The invention of claim 2 of the present application is characterized in that the flange portion of the receptacle has a larger joint area than the joint portion of the connection ring.

According to a third aspect of the present invention, a converging lens in which an annular flange portion and a convex lens portion are provided coaxially, an annular spacer for holding an outer peripheral portion of the lens, and a lens light A semiconductor laser mounted coaxially with the shaft, a spacer, a lens, and a cylindrical element holder that holds the semiconductor laser coaxially, a cylindrical portion that is slidable in the axial direction into which the element holder is inserted, and the cylindrical portion. A connection ring having a joint portion having a joint surface perpendicular to the central axis formed at one end thereof, a flange portion joined to the joint surface of the connection ring, and a receptacle having a cylindrical portion coaxially formed with the flange portion; A ferrule that is detachably attached to the cylindrical portion of the receptacle and holds the optical fiber coaxially; and slide the cylindrical portion of the connection ring and the cylindrical portion of the outer peripheral surface of the element holder in the axial direction. While the connection between Le ring is slid in the axial direction perpendicular plane to emit a semiconductor laser, it is characterized in that each fixed in position to be incident on the optical fiber.

The invention according to claim 4 of the present application is characterized in that the lens is an aspherical lens.

According to a fifth aspect of the present invention, a spherical ball lens, a semiconductor laser mounted coaxially with the optical axis of the ball lens and having a protective cap for emitting laser light,
A lens that is mounted between the semiconductor laser and the ball lens and that converges the emitted light of the semiconductor laser; a lens cap that holds the lens coaxially and is joined to the stem of the semiconductor laser; and a lens cap and the semiconductor laser that are coaxial. The cylindrical element holder held in the device, the fixing portion having the joint surface for joining the cylindrical end surface of the element holder and the insertion hole of the ball lens, and the cylindrical portion formed coaxially with the fixing portion are integrally formed. A receptacle and a ferrule that is detachably attached to the cylindrical portion of the receptacle and holds the optical fiber coaxially;
The semiconductor laser emits light while sliding the receptacle and the element holder in a plane perpendicular to the axial direction, and the semiconductor laser is fixed at a position where the semiconductor laser is incident on the optical fiber.

According to a sixth aspect of the present invention, the effective diameter of the ball lens is larger than the effective diameter of the lens.

In the invention of claim 7 of the present application, the lens converts the laser light emitted from the semiconductor laser into parallel light, and the ball lens condenses the parallel light emitted from the lens into an optical fiber. It is characterized by making it incident.

The invention of claim 8 of the present application is a prismatic lens in which the periphery of a ball lens is cut into a quadrangular prismatic shape or at least two parallel surfaces are cut into a flat surface, and a U-shaped notch is formed along the central axis of the prismatic lens. A lens holder having a hole and holding a prismatic lens, a semiconductor laser with a protective cap that is mounted coaxially with the optical axis of the prismatic lens, and emits laser light, is mounted between the semiconductor laser and the prismatic lens,
A lens that converges emitted light of a semiconductor laser, a lens cap that holds the lens coaxially and is joined to a stem of the semiconductor laser, a cylindrical element holder that holds the lens cap and the semiconductor laser coaxially, and an element holder And a receptacle having a joint surface to be joined to the cylindrical end surface of the lens holder and an insertion hole of the lens holder, a receptacle integrally formed with a cylindrical portion formed coaxially with the fixing portion, and detachable from the cylindrical portion of the receptacle. And a ferrule that holds the optical fiber coaxially, and that makes the semiconductor laser emit light while sliding the receptacle and the element holder in a plane perpendicular to the axial direction,
It is characterized in that it is fixed at a position where it is incident on the optical fiber.

The invention according to claim 9 of the present application is characterized in that a lens cap to which a lens is fixed is joined to a stem instead of a protective cap of a semiconductor laser, and a laser chip of the semiconductor laser is sealed from the outside air. Is.

The invention according to claim 10 of the present application is characterized in that the central axes of the semiconductor laser and the lens cap are arranged so as not to coincide with the optical axis of the optical fiber.

[0021]

According to the invention of claim 1 of the present application having such a feature, since the lens and the semiconductor laser are incorporated in the element holder and the lens is fixed at the same time, the step of fixing the lens can be omitted. Further, the position of the element holder to which the lens and the semiconductor laser are fixed is moved in the axial direction with respect to the connecting ring, and the connecting ring is further moved in the direction perpendicular to the axis of the receptacle. Then, it is fixed at a position where light is incident on the optical fiber. This makes it possible to easily assemble a semiconductor module having high coupling efficiency.

According to the invention of claim 2 of the present application, in the receptacle and the connection ring for position adjustment, the flange portion of the receptacle is made larger than the joint portion of the connection ring, so that the connection ring is slightly moved for position adjustment. Even
The connecting ring always abuts the receptacle completely. Therefore, both parts can be completely adhered and fixed.

According to the invention of claim 3 of the present application, the focal length of the lens is adjusted through the spacer, and the light emitting portion of the semiconductor laser is positioned at this focal point. This makes it possible to fix the lens, the spacer, and the semiconductor laser at the same time without using the lens holder.

According to the invention of claim 5 of the present application, an optical system having high coupling efficiency is constructed by using a lens cap having a lens having a large effective aperture and a ball lens. Then, the ball lens inserted into the receptacle and the optical fiber held by the ferrule are positionally adjusted in a direction perpendicular to the optical axis, and fixed at a position where light is incident on the optical fiber.

According to the invention of claim 6 of the present application, since the effective aperture of the ball lens is larger than the lens of the lens cap, all the laser light emitted from the lens of the lens cap can be condensed by the ball lens. Therefore, high coupling efficiency can be obtained.

According to the invention of claim 7 of the present application, the lens of the lens cap collimates the laser beam and the ball lens focuses the collimated beam. Therefore, the element holder and the receptacle are coupled by parallel light, and high coupling efficiency can be obtained by only adjusting the optical axis in the direction perpendicular to the central axis.

According to the invention of claim 8 of the present application, a ball lens is cut into a quadrangular prism shape to form a prismatic lens, and the lens has a cylindrical outer shape and a U-shaped inner surface. The prism lens can be easily fixed to the receptacle by inserting and fixing it in the holder.

Further, according to the invention of claim 10 of the present application, the laser light reflected from the lens surface is incident on the lens cap and the ball lens from the semiconductor laser whose center axis is deviated, and the laser light reflected by the lens surface is emitted from the semiconductor laser. Will not return to. Therefore, the oscillation of the semiconductor laser becomes stable.

[0029]

EXAMPLE An optical semiconductor module of Example 1 of the present invention will be described with reference to FIG. FIG. 1 is a vertical sectional view showing the configuration of the optical semiconductor module of the first embodiment. In the figure, the semiconductor laser 10 is attached to an element holder 11. In the semiconductor laser 10, a laser chip (not shown) is mounted on the stem 10a as in the conventional example, and the protective cap 10b is joined to the stem 10a.

The element holder 11 is a holder for holding the semiconductor laser 10, the lens 12, and the lens holder 13, respectively, and is made of an iron-based metal formed in a stepped cylindrical shape. Inside the cylindrical portion 11a located below the element holder 10,
Similarly, it is cut out into a stepped cylindrical shape to accommodate the stem 10a of the semiconductor laser 10 and the protective cap 10b. Further, the inside of the elongated cylindrical portion 11b located above the element holder 11 is also cut out into a stepped cylindrical shape, and the cylindrical lens holder 13 is inserted. The lens 12 is the semiconductor laser 10
The NA (numerical aperture) value of the aspherical lens for converging the laser light is, for example, 0.5 and is inserted into the lens holder 13.

A connecting ring 14 is inserted into the outer peripheral surface of the cylindrical portion 11b of the element holder 11. The connection ring 14 is a ring that connects the element holder 11 and a receptacle 15 described later, and is made of iron-based metal. Connection ring 14
The thin cylindrical portion 14a and the thick joint portion 14b are integrally formed. The inner surface of the cylindrical portion 14a is finished so as to be slidable in the optical axis direction of the laser beam with respect to the cylindrical portion 11b of the element holder 11, and is welded at an optimum position during assembly. Also, the joint portion 14 in the connection ring 14
The upper end surface of b is processed flat so as to form an annular joint surface, and is slidable in a plane perpendicular to the optical axis direction with respect to the connection end surface of the receptacle 15 before welding.

The receptacle 15 holds the ferrule 16 coaxially and makes laser light enter the optical fiber 17. The receptacle 15 is also made of iron-based metal, and the flange portion 15a and the cylindrical portion 15b are integrally formed.
The lower end surface of the flange portion 15a is finished to be flat and has a larger joint area than the connecting portion 14b of the connecting ring 14. A hole 15c is formed in the center of the flange portion 15a so that laser light can be incident on the optical fiber 17.

The ferrule 16 holds the end of the optical fiber 17 coaxially and has a function of aligning the core end face of the optical fiber 17 with the optical axis of the semiconductor laser 10. The lower end surface of the ferrule 16 is mirror-finished and comes into contact with the flange portion 15a. Further, a flange is formed above the ferrule 16 to facilitate the insertion / removal with respect to the receptacle 15.

To assemble an optical semiconductor module composed of such components, first, the lens 12 is press-fitted and fixed in the lens holder 13. Next, the lens holder 13 to which the lens 12 is attached and the semiconductor laser 10 are inserted in this order from below the cylindrical portion 11a of the element holder 11. Then, the YAG laser beam is applied to the portion indicated by the arrow P1 while pressure is applied upward from the stem 10a of the semiconductor laser 10 to weld the semiconductor laser 10 and the element holder 11. By this process, the lens holder 13 with the lens 12 fixed
Is in contact with the protective cap 10b at the inner contact surface of the cylindrical portion 11b, and is sandwiched and fixed between the element holder 11 and the semiconductor laser 10. When the lens holder 13 and the element holder 11 are securely fixed, the portion indicated by arrow P2 may be irradiated with YAG laser light and welded.

Next, the optical fiber 17 is inserted into the center hole of the ferrule 16 and fixed, and the tip surface of the ferrule 16 is mirror-polished. And ferrule 16 into receptacle 15
To insert. The laser light emitted from the semiconductor laser 10 is condensed by the lens 12. The condensed laser light passes through the hole 15c of the receptacle 15. At this time, the joint portion 14b of the connection ring 14 is positioned with respect to the flange portion 15a so that the laser light is incident on the optical fiber 17 as much as possible. Then, the connection ring 14 is finely moved in the optical axis direction with respect to the element holder 11. Further receptacle 15
On the other hand, the joint portion 14b of the connection ring 14 is finely moved again in the direction perpendicular to the optical axis to detect where the amount of incident light on the optical fiber 17 is maximized.

Since the NA value of the lens 12 is as large as 0.5, the coupling efficiency with the optical fiber 17 having the core diameter of 50 μm reaches 90% at maximum. Since the cylindrical portion 14a, which is the welded portion of the connection ring 14, has a thin plate thickness of 0.2 mm,
The portion indicated by the arrow P3 can be easily welded and fixed by the YAG laser light. Next, the connection ring 14 is moved again with respect to the receptacle 15 in the direction perpendicular to the optical axis, and the portion indicated by the arrow P4 is irradiated with the YAG laser light at a position where the amount of light incident on the optical fiber 17 is maximized to perform welding. . The flange portion 15a of the receptacle 15 is in contact with the upper surface of the connection ring 14, and the contact surface of the flange portion 15a is the joint portion 1
Wider than the contact surface of 4b. Therefore, even if the connection ring 14 is moved together with the element holder 11 in the direction perpendicular to the optical axis, the position of the connection ring 14 can be stably adjusted within the range of the flange portion 15a of the receptacle 15. That is, since the two are always in close contact with each other on a plane, the optical axis of the laser light does not tilt with respect to the optical fiber 17 during the adjustment.

As described above, according to the optical semiconductor module of the first embodiment, the light utilization efficiency of the semiconductor laser 10 is improved, and the optical axis of the semiconductor laser 10 and the optical axis of the optical fiber 17 can be surely aligned. Also, the axial distance between the element holder 11 and the receptacle 15 at the coupling portion can be surely adjusted. Furthermore, when the lens 12 and the semiconductor laser 10 are inserted and fixed in the element holder 11, the lens 12 is sandwiched between the element holder 11 and the semiconductor laser 10, so that the step of fixing the lens 12 can be omitted. Further, since the contact surface between the receptacle 15 and the connection ring 14 is larger than the connection ring 14, the edge of the connection ring 14 does not protrude from the edge of the receptacle 15, and both can be reliably welded with the YAG laser light.

Next, an optical semiconductor module according to the second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a vertical cross-sectional view showing the structure of the optical semiconductor module of the second embodiment. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted. Also in this figure, the semiconductor laser 10 has the element holder 11
Mounted on. Inside the cylindrical portion 11b of the element holder 11, a stepped cylindrical surface similar to that of the first embodiment is formed.
0 is held via the spacer 21.

The lens 20 is a lens in which a lens portion having a convex sectional shape along the optical axis as shown in the figure and a flange portion 20a having an annular outer periphery are integrally formed. Further, the spacer 21 has substantially the same shape as the flange portion 20a, and functions to maintain the mounting height of the lens 20 to the laser chip (not shown) of the semiconductor laser 10 at a predetermined value. In addition, the connection ring 14, the receptacle 15,
The shape of the ferrule 16 is the same as that of the first embodiment, and the description of the configuration is omitted.

Regarding the assembling method and the operation of the optical semiconductor module of the second embodiment thus constructed, only the parts different from those of the first embodiment will be explained. Even without the lens holder 13 as shown in FIG. 1, the mounting position of the laser chip of the semiconductor laser 10 must be on the focal point of the lens 20. Therefore, a spacer 21 having a predetermined thickness is attached between the protective cap 10b and the lens 20 to align the lens 20 and the laser chip. Since the spacer 21 has a cylindrical shape, the laser light emitted from the semiconductor laser 10 enters the lens 20 without being blocked by the spacer 21. Even if the spacer 21 and the lens 20 are sandwiched between the element holder 11 and the semiconductor laser 10, the force is only applied to the flange 20a, and the lens body of the lens 20 is less likely to be distorted. After adjusting the positions of the respective parts, welding with YAG laser light to the portions indicated by arrows P5 to P8 is the same as in the first embodiment.

As described above, according to the second embodiment, the lens 2
0 and the semiconductor laser 10 with a spacer 21 inserted,
By putting these in the element holder 11 and fixing them,
The lens 20 and the spacer 21 can be fixed at the same time. Also, by adjusting the thickness of the spacer 21, the head chip of the semiconductor laser 10 can be easily positioned at the focal position of the lens 20.

Next, an optical semiconductor module according to the third embodiment of the present invention will be described with reference to FIG. FIG. 3 is a vertical cross-sectional view showing the structure of the optical semiconductor module of the third embodiment. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted. In the figure, the semiconductor laser 10 is attached to an element holder 30 having a shape different from that of the above-described embodiment. The element holder 30 is a cylindrical member whose outer diameter is the semiconductor laser 10.
The stem 10a has substantially the same diameter.

Inside the element holder 30, a lens cap 32 to which a lens 31 is fixed is attached. The lens cap 32 is attached to the outside of the protective cap 10b so that the focus of the lens 31 matches the attachment position of the laser chip. The lens 31 is a thick lens having a central portion formed in a convex shape and an outer peripheral portion formed in a cylindrical shape and having a diameter of 4 mm, and collimates laser light emitted from the semiconductor laser 10.

Next, a receptacle 34 having a ball lens 33 therein is attached to the upper joint surface of the element holder 30. The ball lens 33 is a spherical lens having a diameter of 5 mm, and is a lens that refracts the parallel light emitted from the lens 31 and converges the laser light on the end surface of the optical fiber 17. The receptacle 34 has a flange portion 34a and a cylindrical portion 34b similarly to the receptacle 15 of FIG. 1, and in particular, the flange portion 34a is integrally connected to a cylindrical fixing portion 34c. The ball lens 3 is provided inside the fixing portion 34c.
3 is held by, for example, press fitting. The shape of the ferrule 16 including the optical fiber 17 and the receptacle 34
The method of attaching the ferrule 16 to is similar to that of the first and second embodiments.

With respect to the assembling method and operation of the optical semiconductor module of the third embodiment having the above-described structure, only the parts different from those of the above-described embodiment will be described. First, the lens 31 is attached to the head of the lens cap 32. Then, the lens cap 32 is covered over the protection cap 10b and welded and fixed to the semiconductor laser 10. At this time, the height of the lens 31 in the lens cap 32 is fixed at a position where the laser light emitted from the semiconductor laser 10 is collimated. Then, the semiconductor laser 10 with the lens cap 32 fixed is inserted into the element holder 30, and the portion indicated by the arrow P9 is welded and fixed using YAG laser light.

Next, the optical fiber 1 is inserted into the hole of the ferrule 16.
7 is inserted and fixed, and the tip portion is mirror-polished. The ferrule 16 is inserted through the hole above the receptacle 34. Further, the ball lens 33 is press-fitted into the hole provided inside the fixing portion 34c. Laser light emitted from the semiconductor laser 10 is converted into parallel light by a lens 31, and the laser light is further focused by a ball lens 33. Next, the element holder 30 is positionally adjusted with respect to the receptacle 34 in the direction perpendicular to the optical axis, and the portion indicated by the arrow P10 is irradiated with YAG laser light at a position where the laser light is efficiently incident on the optical fiber 17 and welded and fixed. .

Since the lens 31 and the ball lens 33 are coupled by quasi-collimated light in a substantially parallel state, even if the distance between the lens 31 and the ball lens 33 changes, the light coupling efficiency hardly changes. Further, since the light is coupled by the quasi-collimated light, even if the incident light is displaced in the direction perpendicular to the central axis of the optical fiber 17, the light coupling efficiency is unlikely to change, and a high coupling efficiency of 30% or more is obtained. be able to.
Further, since the ball lens 33 has a larger effective aperture than the lens 31, all the laser light emitted from the lens 31 enters the ball lens 33. Therefore, the coupling efficiency with the optical fiber 17 can be further increased.

Thus, according to the optical semiconductor module of the third embodiment, the semiconductor laser 10 is covered with the lens cap 32 having the lens 31, and the optical fiber 17 and the ball lens 33 are connected by the receptacle 34. Further, by coupling the lens cap 32 and the ball lens 33 with quasi-collimated light, it is possible to omit the axial adjustment and simplify the optical axis adjustment. Further, the ball lens 33
Is larger than the cross section of the lens cap 32, most of the laser light emitted from the lens cap 32 can be condensed by the ball lens 33.

With such a configuration, the coupling efficiency of the laser light to the optical fiber 17 can be increased. Although the semiconductor laser 10 having the protective cap 10b is covered with the lens cap 32, the semiconductor laser 10 not having the protective cap 10b may be covered with the lens cap 32, and the contact portions between the two may be hermetically welded and fixed. Needless to say.

Next, an optical semiconductor module according to a fourth embodiment of the present invention will be described with reference to FIGS. Figure 4 is the fourth
It is a longitudinal cross-sectional view showing the configuration of the optical semiconductor module of the embodiment, and the same parts as those of the third embodiment are designated by the same reference numerals and the description thereof will be omitted. Also in this figure, the semiconductor laser 10 is attached to the same element holder 30 as in the third embodiment, and the element holder 30 is also coupled to the same receptacle 34 as in FIG.

Unlike the third embodiment, a prismatic lens 40 having a part of the spherical surface cut into a flat surface is used. The prismatic lens 40 is held by a lens holder 41. 5A and 5B are diagrams showing the shapes of the prismatic lens 40 and the lens holder 41. FIG. 5A is a cross-sectional view taken at a right angle to the optical axis, and FIG. 5B is a front view seen from a plane parallel to the optical axis. c) is a side view seen from a plane parallel to the optical axis. That is, the lens holder 41 has a cylindrical outer peripheral surface, and a part of the lens holder 41 is cut off in a flat shape as shown in FIG. Further, the inside of the lens holder 41 is cut out into a prismatic shape, and one of the four side surfaces is cut off. As shown in FIGS. 5B and 5C, the prismatic lens 40 is formed such that the lower entrance surface and the upper exit surface are part of a spherical surface, and the four side surfaces along the optical axis are planar. Has been cut into.

Regarding the assembling method and operation of the optical semiconductor module of the fourth embodiment thus constructed, only the parts different from those of the third embodiment will be explained. First, as shown in the cross-sectional view of FIG. 5A, the ball lens is cut into four sides so that the side faces are quadrangular prisms, and the prismatic lens 40 is formed.
Next, the prismatic lens 40 is press-fitted or adhesively fixed to a lens holder 41 whose inside is cut into a U-shape. Figure 5
In the prismatic lens 40 fixed to the lens holder 41 as in (a) and (b), since the light incident surface and the light emitting surface are physically limited, an antireflection film is attached to this surface.

In this way, the prismatic lens 40 is press-fitted and fixed in the mounting hole 34d of FIG. 4 via the render holder 41. The laser light emitted from the semiconductor laser 10 becomes parallel light and enters the prismatic lens 40. Then, the laser light that has passed through is converged and enters the optical fiber 17. Since the entrance surface and the exit surface of the prismatic lens 40 are coated with an antireflection film, the light coupling efficiency is increased as much as the amount of reflection on each surface is reduced.

By thus inserting and fixing the prismatic lens 40 into the lens holder 41 having a cylindrical outer shape, the prismatic lens 40 can be easily fixed to the receptacle 34. Further, since the surface through which the laser light is transmitted can be limited in the prismatic lens 40, it is sufficient to provide an antireflection film only on this transmission surface, the light transmittance can be increased, and the coupling efficiency with the optical fiber can be further improved. .

Next, an optical semiconductor module according to the fifth embodiment of the present invention will be described with reference to FIG. FIG. 6 is a longitudinal sectional view showing the structure of the optical semiconductor module of the sixth embodiment, and the constituent parts are the same as those of the third embodiment. Therefore, the reference numerals of the components are the same as those in the third embodiment, and the description thereof will be omitted.

In this embodiment, the head chip 10c of the semiconductor laser 10 is attached while being displaced from the central axis of the lens 31. Laser light B emitted from the laser chip 10c
1 spreads obliquely and enters the lens 31. Then, when passing through the lens 31, it is converted into parallel laser light B2. The parallel laser light B2 is incident on the ball lens 33 with an inclination with respect to the upper and lower central axes and becomes converged laser light B3. The laser beam B3 is emitted from the ferrule 16
It is incident on the optical fiber 17 held by.

In order to make the laser light enter the optical fiber 17 in this way, the element holder 30 is finely moved in the direction perpendicular to the optical axis with respect to the receptacle 34, and the optical axis is adjusted. The element holder 30 and the receptacle 34 are fixed at a position where the incident light on the optical fiber 17 is maximized, and the portion indicated by the arrow P10 is welded with YAG laser light. By doing so, the laser light emitted from the laser chip 10c obliquely enters the lens 31, the ball lens 33, and the optical fiber 17,
The light reflected by each reflecting surface does not return to the laser chip 10c. Therefore, no light energy is applied to the laser chip 10c, and noise and distortion of oscillation can be reduced.

[0058]

As described above, according to the inventions of claims 1 and 4 of the present application, the cylindrical portion of the connecting ring and the outer peripheral surface of the element holder are moved in the axial direction, and the flange portion of the receptacle and the connecting portion of the connecting ring are moved. The optical axis can be adjusted by moving in the direction perpendicular to the axis. Therefore, the lens and the semiconductor laser can be assembled in the element holder and the lens can be fixed at the same time. Therefore, the step of fixing the lens can be omitted, and the semiconductor laser and the optical fiber can be coupled.

According to the second and fourth aspects of the present invention, in addition to the effects described above, the receptacle and the connection ring are always in contact with each other even if the position of the connection ring is slightly moved in the direction perpendicular to the optical axis. Therefore, it is possible to closely fix each component by welding or the like.

According to the third and fourth aspects of the present invention, the focus of the lens can be easily adjusted to the light source of the semiconductor laser by providing the spacer even when the lens holder is not provided.

Further, according to the invention of claim 5 of the present application, since the beam diameter of the laser beam passing between the lens for converging the laser beam and the ball lens is large, the receptacle and the element holder are provided with an optical axis. The optical axis can be adjusted simply by making a slight movement in the direction perpendicular to.

According to the invention of claim 6 of the present application, in addition to the action of the invention of claim 5, since the effective apertures of the lens and the ball lens are large, an optical system with high coupling efficiency can be realized.

According to the invention of claim 7 of the present application, since the laser light passing between the lens and the ball lens is parallel, it is high only by adjusting the optical axis only in the direction perpendicular to the central axis. Coupling efficiency can be realized.

Further, according to the invention of claim 8 of the present application, since the prismatic lens obtained by cutting the ball lens into a quadrangular prism is attached to the lens holder, this lens can be easily fixed to the receptacle.

According to the invention of claim 9 of the present application, the protective cap of the semiconductor laser itself can be eliminated by hermetically attaching the lens cap with the lens to the semiconductor laser.

Further, according to the invention of claim 10 of the present application, the laser light emitted from the semiconductor laser is obliquely incident on the incident surfaces of the lens, the ball lens, and the optical fiber, respectively, and therefore is reflected by these optical systems. The emitted light does not return to the semiconductor laser. Therefore, the noise and distortion of the oscillation of the semiconductor laser can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration of an optical semiconductor module according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a configuration of an optical semiconductor module according to a second embodiment of the present invention.

FIG. 3 is a sectional view showing a configuration of an optical semiconductor module according to a third embodiment of the present invention.

FIG. 4 is a sectional view showing the structure of an optical semiconductor module according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of a lens and a lens holder used in the optical semiconductor module of the fourth embodiment.

FIG. 6 is a sectional view showing a configuration of an optical semiconductor module according to a fifth embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a configuration example of a conventional optical semiconductor module device.

[Explanation of symbols]

 10 Semiconductor Laser 10a Stem 10b Protective Cap 10c Laser Chip 11,30 Element Holder 11a, 11b, 14a, 15b, 34b Cylindrical Part 12, 20, 31 Lens 13, 41 Lens Holder 14 Connection Ring 14b Joining Part 15, 34 Receptacle 15a, 20a, 34a Flange portion 15c Hole 16 Ferrule 17 Optical fiber 21 Spacer 30a Bonding surface 32 Lens cap 33 Ball lens 34c Fixing portion 34d Mounting hole 40 Square prism lens

Claims (10)

[Claims] 1. A converging lens inserted and fixed in a cylindrical lens holder, a semiconductor laser mounted coaxially with the optical axis of the lens, and a cylinder for holding the lens holder and the semiconductor laser coaxially. -Shaped element holder, a cylindrical portion that is slidable in the axial direction into which the element holder is inserted, and a connection ring in which a joint portion having a joint surface perpendicular to the central axis is formed at one end of the cylindrical portion, A receptacle having a flange portion joined to the joining surface of the connection ring, and a cylindrical portion formed coaxially with the flange portion, and a ferrule that is detachably attached to the cylindrical portion of the receptacle and holds the optical fiber coaxially. By sliding the cylindrical part of the connection ring and the cylindrical part of the outer peripheral surface of the element holder in the axial direction, and sliding the receptacle and the connection ring in a plane perpendicular to the axial direction. An optical semiconductor module, wherein the semiconductor laser is caused to emit light while being fixed, and the semiconductor lasers are fixed at positions where they are incident on the optical fiber. 2. The optical semiconductor module according to claim 1, wherein the flange portion of the receptacle has a joint area larger than that of the joint portion of the connection ring. 3. A converging lens in which an annular flange portion and a convex lens portion are provided coaxially, an annular spacer for holding an outer peripheral portion of the lens, and an optical axis which is attached coaxially with the optical axis of the lens. Semiconductor laser, a cylindrical element holder that coaxially holds the spacer, the lens, and the semiconductor laser, a cylindrical portion that is slidable in the axial direction in which the element holder is inserted, and the cylindrical portion. A connection ring having a joint portion having a joint surface perpendicular to the central axis at one end, a flange portion that is joined to the joint surface of the connection ring, and a receptacle having a cylindrical portion coaxially formed with the flange portion, A ferrule that is removably attached to the cylindrical portion of the receptacle and holds the optical fiber coaxially; and the cylindrical portion of the connection ring and the outer peripheral cylindrical portion of the element holder are axial An optical semiconductor, wherein the semiconductor laser is caused to emit light while sliding the receptacle and the connection ring in a plane perpendicular to the axial direction, and the semiconductor laser is fixed at a position to be incident on the optical fiber. module. 4. The optical semiconductor module according to claim 1, wherein the lens is an aspherical lens. 5. A ball lens having a spherical shape, a semiconductor laser mounted coaxially with the optical axis of the ball lens and emitting a laser beam, and mounted between the semiconductor laser and the ball lens. A lens for converging the emitted light of the semiconductor laser, a lens cap for holding the lens coaxially and joined to the stem of the semiconductor laser, and a cylindrical shape for holding the lens cap coaxially with the semiconductor laser. An element holder, a fixed portion having a joint surface that is joined to a cylindrical end surface of the element holder and an insertion hole of the ball lens, a receptacle integrally formed with a cylindrical portion formed coaxially with the fixed portion, A ferrule that is removably attached to the cylindrical portion of the receptacle and holds the optical fiber coaxially; and the receptacle and the element holder. The optical semiconductor module, characterized by preparative is emitting the semiconductor laser while sliding in the axial direction perpendicular plane, fixed in a position that is incident on the optical fiber. 6. The optical semiconductor module according to claim 5, wherein the effective diameter of the ball lens is larger than the effective diameter of the lens. 7. The lens converts laser light emitted from the semiconductor laser into parallel light, and the ball lens collects parallel light emitted from the lens and makes the parallel light incident on the optical fiber. The optical semiconductor module according to claim 5, wherein the optical semiconductor module is an optical semiconductor module. 8. A prismatic lens in which the periphery of a ball lens is cut into a quadrangular prismatic shape or at least two planes parallel to each other are flattened, and a U-shaped cutout hole is provided along the central axis of the prismatic lens, A lens holder that holds a lens; a semiconductor laser that is mounted coaxially with the optical axis of the prismatic lens and that emits laser light; and a semiconductor laser that is mounted between the semiconductor laser and the prismatic lens. A lens for converging the emitted light, a lens cap that holds the lens coaxially, and is joined to the stem of the semiconductor laser, and a cylindrical element holder that holds the lens cap and the semiconductor laser coaxially. A fixed portion having a joint surface that is joined to the cylindrical end surface of the element holder and an insertion hole of the lens holder, and a cylindrical portion that is formed coaxially with the fixed portion. A receptacle formed in the body, and a ferrule that is removably attached to the cylindrical portion of the receptacle and holds the optical fiber coaxially, and the receptacle and the element holder are in a plane perpendicular to the axial direction. An optical semiconductor module, wherein the semiconductor laser is caused to emit light while sliding, and is fixed at a position where it is incident on the optical fiber. 9. The lens cap, to which the lens is fixed, is joined to a stem instead of the protective cap of the semiconductor laser, and the laser chip of the semiconductor laser is sealed from the outside air. 8. The optical semiconductor module according to item 8. 10. The optical semiconductor module according to claim 5, wherein the center axes of the semiconductor laser and the lens cap are arranged so as not to coincide with the optical axis of the optical fiber.