JP2002258115A - Optical module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly versatile surface mount type optical module in which the intensity of outgoing light from a surface-emitting poetical element can surely be monitored with a simple structure, in which the optical axis is made parall to the surface of a substrate, and whose profile can be made low. SOLUTION: On a substrate 1, a chip carrier provided with a surface-emitting optical element 3, an optical fiber 5 whose end is obliquely machined for optically connecting one end to the optical element 3, and a light receiving element 4 for monitoring the output light of the optical element 3. The machined end face of the optical fiber 5 made to face the light receiving element 4, and the light receiving element 4 is disposed to be opposite to the surface-emitting optical element 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical module in which an optical fiber for light transmission and a light receiving element for monitoring light emitted from the light emitting element are optically connected to a light emitting element disposed on a substrate. About.

[0002]

2. Description of the Related Art Until now, many optical modules have been proposed in which an edge emitting device and an optical fiber for optically connecting (optical coupling) to the substrate are mounted on a substrate, but a mode field of light emitted from the edge emitting device has been proposed. Because the shape is not a perfect circle,
Even when optically connected to an optical fiber via a lens or the like, coupling loss is large.

Further, an optical module using a surface light emitting element has been proposed in order to make the mode field shape a perfect circle. However, it is more difficult to monitor the output of the surface light emitting element than the edge light emitting element. Therefore, it is difficult to control the emitted light from the monitor information. Although a method of forming a monitor light receiving element on the back surface of the surface light emitting element has been proposed, the manufacturing process of the element becomes complicated.

[0004] A method of monitoring the light output in a conventional optical module having a surface light emitting element will be described. As shown in FIG. 7, the surface light emitting element 3 and the light receiving element 4 mounted on the same lead frame 11 are integrally sealed with a resin 12 transparent to the wavelength of the light emitted from the surface light emitting element 3. And
The condensing lens 6 and the position deviated from the optical axis around the condensing lens 6 on the optical axis extension of the surface emitting element 3
The reflection mirror 7 that reflects the leaked light 22, that is, light that is not coupled to the optical fiber, and makes the light incident on the light receiving element 4 is formed. With such a configuration, the intensity of the light emitted from the surface light emitting element 3 is monitored (for example, see Japanese Unexamined Patent Application Publication No.
321900). In the figure, reference numeral 21 denotes coupling light, and reference numeral 23 denotes reflected light.

[0005] Further, as shown in FIG. 8, a light receiving element is arranged at a position deviated from the optical axis around the optical axis of the surface light emitting element 3 to monitor the leaked light 22 of the light emitted from the surface light emitting element 3. (For example, see Japanese Patent Application Laid-Open No. H11-274650). In the figure, 13 is a metal cap (sealed body), 14
Is a glass window, 15 is a ferrule, and 16 is a ferrule holder. The same components as those in FIG. 7 are denoted by the same reference numerals and description thereof is omitted.

Further, in order to provide a highly versatile surface-mount type optical module in which the optical axis is parallel to the substrate surface and the height can be reduced, as shown in FIG. A method has also been proposed in which a surface light emitting element 3 is mounted on the surface of a light emitting element 1 and an optical fiber 5 having a short portion obliquely processed and a reflection mirror 7 provided at the tip is disposed above the light emitting portion (for example, JP-A-2000-292656). reference). Note that the same components as those in FIG. 7 are denoted by the same reference numerals and description thereof is omitted.

[0007]

However, in the optical module shown in FIG. 7, in order for light to enter the optical fiber 5, it is necessary to adjust the optical axis while driving the surface light emitting element 3. In the optical module shown in FIG. 8, in order to make light incident on the optical fiber 5 and take out light output to the outside,
A component for holding the optical fiber 5 is required, and the structure becomes very complicated.

In the optical module shown in FIG. 9, the output from the surface light emitting element 3 cannot be monitored.
Although the optical fiber 5 and the surface emitting element 3 need to be strictly aligned, the optical fiber is restricted in the left-right direction by a groove formed in the substrate 1 and cannot be finely adjusted. There was a problem that it was not possible.

The present invention has been made in view of such a problem, and it is possible to reliably monitor the intensity of the output light from the surface light emitting element 3 with a simple configuration and to control the optical axis with respect to the surface of the substrate 1. It is an object of the present invention to provide a highly versatile surface-mount type optical module capable of reducing the height and making it parallel.

[0010]

In order to achieve the above object, an optical module according to the present invention comprises a light emitting element provided on a substrate, an optical fiber and a light receiving element for monitoring the light emitted from the light emitting element. An optical connection is made, and at least the light incident end of the optical fiber and the light receiving element are fixed to the carrier base, and the light incident end of the optical fiber is connected to the light emitting part of the light emitting element and the light receiving element. It is characterized by being located between the light receiving unit.

Further, a light incident end of the optical fiber is formed on an inclined surface, and the inclined surface faces a light receiving portion of the light receiving element. Further, the light emitting device is a surface light emitting device. Further, the substrate and the carrier base are formed of single crystal silicon.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an optical module according to the present invention will be described below in detail with reference to the drawings schematically showing the embodiments.

As shown in FIGS. 1 and 2, an optical fiber holding groove 31, a surface light emitting element mounting step 32, and a surface are formed on a substrate 1 made of a material capable of anisotropic etching such as silicon single crystal. A light emitting element mounting electrode (not shown), a surface light emitting element driving electrode 42, and a chip carrier mounting electrode 43 are formed. Solder 51 is mounted on a mounting portion of the surface light emitting element mounting electrode and the chip carrier mounting electrode 43. Form.

A chip carrier 2, which is a carrier base shown in FIG. 3, is made of the same material as the substrate 1. On the chip carrier 2, an optical fiber mounting groove 33, a light receiving element mounting step 34, a light receiving element A mounting electrode (not shown) and a light receiving element driving electrode 45 are formed, and solder 51 is formed on a mounting portion of the light receiving element mounting electrode.

As shown in FIGS. 4 and 5, a surface light emitting element 3 is mounted on a substrate 1 and a light receiving element 4 is mounted on a chip carrier 2.
And the optical fiber 5 are mounted. Further, the surface light emitting element 3 includes the substrate 1 and the light receiving element 4 includes the chip carrier 2.
Are electrically connected by wire bonding.

As described above, in the optical module of the present invention, the optical fiber 5 and the light receiving element 4 for monitoring the light emitted from the surface light emitting element 3 are optically connected to the surface light emitting element 3 disposed on the substrate 1. At least the light incident end of the optical fiber 5 and the light receiving element 3 are fixed to the chip carrier 2, and the light incident end of the optical fiber 5 is connected to the light emitting part of the surface light emitting element 3 and the light receiving part of the light receiving element 4. It is located between.
Also, the light incident end of the optical fiber 5 is formed on an inclined surface,
The inclined surface faces the light receiving portion of the light receiving element 4. Further, the substrate 1 and the chip carrier 2 are characterized in that they are particularly formed of single crystal silicon.

Thus, as shown in FIG. 6, by mounting the chip carrier 2 on the substrate 1, the coupled light 21 of the light emitted from the surface light emitting element 3 has the tip mounted on the chip carrier 2. The light is reflected by the end face of the optical fiber 5 formed obliquely, and can be extracted to the outside through the optical fiber 5. Further, the leaked light 22 not coupled to the optical fiber 5 enters the light receiving element 4 and the light output is monitored.

As described in detail above, according to the optical module of the present invention, the surface light emitting element 3 is mounted on the bottom of the surface light emitting element mounting step 32 on the substrate 1, and the optical fiber mounting groove on the chip carrier 2. By mounting the light receiving element 4 on the bottom of the optical fiber 5 whose end face is obliquely processed and the light receiving element mounting step 34 and mounting the chip carrier 2 on the substrate 1, the light emitted from the surface light emitting element 3 The light is reflected by the end face of the optical fiber 5 that has been obliquely processed and optically coupled to the optical fiber 5.

Further, the outgoing light not coupled to the optical fiber 5 becomes the leak light 22 and enters the light receiving element 4 so that the light output can be monitored.

Further, by adopting a structure in which the light receiving element 4 and the optical fiber 5 are mounted on the chip carrier 2, the surface light emitting element 3 can be aligned with the optical fiber 5 requiring the highest positional accuracy. Positioning can be performed in an arbitrary direction with respect to a plane parallel to the substrate plane with reference to the light emitting point No. 3, and the positional deviation of the surface light emitting element 3 mounted on the substrate 1 can be corrected. Thereby, the light emitted from the surface light emitting element 3 can be reliably coupled to the optical fiber 5. This is because it is much easier to position the substrate 1 and the chip carrier 2 than to individually align the surface light emitting element 3 and the optical fiber 5 with respect to the substrate.

Further, since the optical axis is arranged parallel to the surface of the substrate 1 and can be easily aligned, a highly versatile surface mount type optical module having a simple configuration can be provided.

[0022]

Next, an optical module embodying the present invention will be described.

First, as shown in FIG. 2, a groove 31 for holding an optical fiber and a step 32 for mounting a surface light emitting element are formed on a substrate 1 made of silicon single crystal having a (100) plane as a principal surface with a Miller index. The silicon single crystal was formed by anisotropic etching using an aqueous solution. In addition, the surface light emitting element mounting electrode 41, the surface light emitting element driving electric wiring 42, and the chip carrier mounting electrode 43 are arranged in the order of Au / Pt /
It was formed on the surface of the substrate 1 with Ti. An Au-Sn alloy solder 51 was formed on the surface light emitting element mounting portion and the chip carrier mounting portion.

Next, the chip carrier 2 shown in FIG.
Similarly, an optical fiber mounting groove 33 and a light receiving element mounting step 34 were formed by anisotropic etching of a silicon single crystal using a KOH aqueous solution from a silicon single crystal having the (00) plane as a main surface. Further, the light-receiving element mounting electrode 44 and the driving electric wiring 45 were formed on the chip carrier 2 with Au / Pt / Ti in the order of upper layer / lower layer. The Au-Sn alloy solder 51 was formed on the light receiving element mounting portion.

Next, the surface light emitting element 3 was mounted on the bottom of the surface light emitting element mounting step 32 formed on the substrate 1, and electrical connection was made by wire bonding. Next, the light receiving element 4 is mounted on the bottom of the step 34 for mounting the light receiving element formed on the chip carrier 2, the electrical connection is performed by wire bonding, and the optical fiber 5 whose end face is obliquely processed to 45 ° is mounted on the chip carrier 2. It was mounted in the optical fiber mounting groove 33 formed above.

Finally, the chip carrier mounting electrode 43 formed on the substrate 1 was mounted so that the shape of the light receiving element driving electrode 45 formed on the chip carrier 2 was overlapped.

In the present invention, an example in which one optical fiber and a light emitting element are optically connected has been described. However, the present invention is not limited to this, and a plurality of optical fibers and a plurality of light emitting elements corresponding to them are required. May be optically connected, and can be appropriately changed and implemented without departing from the gist of the present invention.

[0028]

According to the present invention, when an optical fiber and a light emitting element are mounted on a substrate, even if the mounting of the light emitting element is displaced,
The optical fiber can be aligned only along the V-groove on which it is mounted, resulting in lower coupling efficiency. However, according to the optical module of the present invention, the optical fiber and the monitoring light receiving element must be mounted on the carrier base. Accordingly, even if the light emitting element is displaced, the optical fiber can be aligned with the carrier substrate, and as a result, the coupling efficiency is improved.

Further, the light incident end of the optical fiber is formed on an inclined surface, and the inclined surface faces the light receiving portion of the light receiving element, so that light emitted perpendicularly to the substrate surface can be emitted. The optical axis can be changed parallel to the substrate surface.

Further, since the light emitting device is a surface light emitting device, the surface light emitting device can be applied to a surface mount type optical module, and a highly versatile optical module can be provided.

Further, since both the substrate and the carrier base are formed of single crystal silicon, anisotropic etching technology can be used, and thereby the optical fiber mounting groove and the marker groove can be formed with high precision. As a result, the mounting accuracy at the time of mounting each optical device can be improved, and the mounting accuracy of the alignment between the substrate and the carrier base can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically illustrating an embodiment of an optical module according to the present invention.

FIG. 2 is a diagram schematically illustrating a substrate of the present invention;
(A) is a plan view and (b) is a side view.

3A and 3B are diagrams schematically illustrating a chip carrier of the present invention, wherein FIG. 3A is a plan view and FIG. 3B is a side view.

4A and 4B are diagrams schematically illustrating a state in which a surface light emitting element is mounted on a substrate of the present invention, wherein FIG. 4A is a plan view and FIG. 4B is a side view.

FIG. 5 is a diagram schematically illustrating a state in which a light receiving element and an optical fiber are mounted on a chip carrier of the present invention;
(A) is a plan view and (b) is a side view.

6A and 6B are diagrams schematically illustrating a state in which the chip carrier of FIG. 5 is mounted on the substrate of FIG. 4; FIG.
(B) is a side view.

FIG. 7 is a cross-sectional view illustrating a conventional optical module.

FIG. 8 is a cross-sectional view illustrating a conventional optical module.

FIG. 9 is a cross-sectional view illustrating a conventional optical module.

[Explanation of symbols]

 1: substrate 2: chip carrier (carrier base) 3: surface light emitting element (light emitting element) 4: light receiving element 5: optical fiber 6: condenser lens 7: reflection mirror 11: lead frame 12: resin 13: metal cap (sealed) Stopper 14: Glass window 15: Ferrule holder 16: Ferrule 21: Coupling light 22: Leakage light 23: Reflected light 31: Optical fiber holding groove 32: Surface light emitting element mounting groove 33: Optical fiber mounting groove 33: Groove for mounting light receiving element 42: Electrode for driving surface light emitting element 43: Electrode for mounting chip carrier 45: Electrode for driving light receiving element 51: Solder

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H037 AA01 BA02 CA10 DA03 DA04 DA06 5F041 AA09 CA12 CA75 DA03 DA07 EE02 EE08 FF14 5F073 AB17 AB28 BA01 EA15 FA02 FA06 FA13 FA22 FA27 5F088 BA16 BB01 EA11 JA03 JA14

Claims (4)

[The claims] 1. An optical module, wherein an optical fiber and a light receiving element for monitoring light emitted from the light emitting element are optically connected to a light emitting element disposed on a substrate, respectively. An incident end and the light receiving element are fixed to a carrier base, and a light incident end of the optical fiber is located between a light emitting part of the light emitting element and a light receiving part of the light receiving element. Optical module. 2. The optical module according to claim 1, wherein a light incident end of the optical fiber is formed on an inclined surface, and the inclined surface faces a light receiving portion of the light receiving element. 3. The optical module according to claim 1, wherein the light emitting device is a surface light emitting device. 4. The optical module according to claim 1, wherein said substrate and said carrier base are made of single crystal silicon.