JPH06188497A - Wavelength-tunable semiconductor light emitting device - Google Patents

Abstract

PURPOSE:To provide a compact semiconductor light emitting device, whose wavelength can be varied, as a high-performance wavelength-tunable light source at a low cost. CONSTITUTION:An outer mirror 13, a movable center beam 14 constituting a microactuator 19 and a fixed comb part 18 are formed on a substrate 11, on which a semiconductor laser 12 is mounted. This is the hybrid type. Or the semiconductor laser, the outer mirror, the movable beam constituting the microactuator and the fixed part are formed on the same substrate in the monolithick type constitution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wavelength tunable semiconductor light emitting device in a semiconductor light source used for systems such as optical communication, optical information processing, and optical measurement.

[0002]

2. Description of the Related Art A surface emitting semiconductor laser and an external mirror are used as a wavelength tunable semiconductor light emitting device in which a mirror used for a system such as optical communication, optical information processing, and optical measurement is directly operated to change a cavity length. Things have already been proposed
(N. Yokouchi et al. IEEE Photonics Tochnology Letter
s, vol.4, no.7,701 (1992)). FIG. 5 shows a schematic perspective view of a conventional wavelength tunable semiconductor light emitting device.

As shown in FIG. 5, a surface-emitting semiconductor laser 102 is formed on a substrate 101 and the substrate 10 is also formed.
An external mirror 104 is formed on the plastic plate 103 attached to the semiconductor laser 1.
A resonator is formed by one surface of No. 2 and the external mirror 104, and the plastic plate 103 is pressed by the tuning rod 105 to displace the external mirror 104 in the optical axis direction, thereby changing the resonator length and the longitudinal mode. It is possible to control.

[0004]

In such a conventional wavelength tunable semiconductor light emitting device, the external mirror 104 is composed of a bulk component, and its adjustment is performed by the tuning rod 1.
It is designed to be performed externally by a piezo or the like via 05. Therefore, there is a problem that an external drive mechanism for adjusting the external mirror 104 is required, the structure becomes complicated and the device itself becomes large.

Further, since this wavelength tunable semiconductor light emitting device is composed of individual components, there is a problem in that its assembly impairs mass productivity and lacks economy. Further, the entire modulator including the external drive mechanism for adjusting the external mirror 104 described above becomes large, resulting in poor space efficiency,
There was also a limitation in increasing the frequency depending on the actuator size of the drive mechanism.

The present invention solves the above-mentioned problems, and solves the problems such as mass production, economic efficiency, and limitation of high frequency due to the external drive mechanism and the individual component structure of the conventional wavelength tunable semiconductor laser. Another object of the present invention is to provide a wavelength tunable semiconductor light emitting device as a small, inexpensive, and high performance wavelength tunable light source.

[0007]

A wavelength tunable semiconductor light emitting device of the present invention for achieving the above object is a semiconductor laser, an external mirror, and a microactuator for driving the external mirror in the optical axis direction of the semiconductor laser. In the wavelength tunable semiconductor light emitting device having :, the external mirror and the microactuator are formed on a substrate on which the semiconductor laser is mounted.

The wavelength tunable semiconductor light emitting device of the present invention is a wavelength tunable semiconductor light emitting device having a semiconductor laser, an external mirror, and a microactuator for driving the external mirror in the optical axis direction of the semiconductor laser. The laser, the external mirror, and the microactuator are formed on the same substrate.

[0009]

By using the micromachining technology to integrally form the external mirror and its driving mechanism on the same substrate, the external mirror, driving mechanism and substrate, or semiconductor laser can be manufactured in a batch, as in the photolithographic LSI process. As compared with the conventional one, the assembling process is remarkably reduced, the mass productivity of the element and the economical efficiency are significantly improved, and the actuator is miniaturized to achieve the high frequency.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a schematic perspective view of a wavelength tunable semiconductor light emitting device according to an embodiment of the present invention, and FIG. 2 is an outline of a forming process showing a method of manufacturing the wavelength tunable semiconductor light emitting device.

As shown in FIG. 1, the wavelength tunable semiconductor light emitting device of this embodiment is of a hybrid type, in which a semiconductor laser 12 is bonded on a Si substrate 11 having a size of about 500 μm × 500 μm for a heat sink. One of the resonators is formed as a resonator, and a movable doubly supported beam 14 that forms an external mirror 13 is formed near one of the resonator surfaces. The both-supported beam 14 is formed of an insulating film 15 that is partially formed.
It has an anchor 16 on its top, one side of which is vertical and serves as the external mirror 13. The other side surface has at least one or more uneven comb-shaped portions 17, and a fixed comb-shaped portion 18 having uneven shapes is formed on the insulating film 15 so as to face the comb-shaped portions 17. In this way, the microactuator 19 is constructed.

Therefore, the electrode pad 2 is formed on the semiconductor laser 12.
0 is formed, and the electrode pads 21 and 22 are attached to the movable double-supported beam 14 and the fixed comb-shaped portion 18, respectively, and a voltage is applied between the two, so that the movable double-supported beam 14 is moved by its electrostatic force. Is driven and the external mirror 13 that reflects the laser light is displaced in the optical axis direction, and the longitudinal mode can be controlled.

Such a wavelength tunable semiconductor laser device is
For example, it is manufactured by the following method. Figure 2 (a)
As shown in (g), first, the insulating film 1 is formed on the Si substrate 11.
After forming 5, the step 23 for bonding the semiconductor laser 12 is formed by, for example, different direction wet etching. Next, a sacrifice layer 23 is formed at a position where the movable doubly supported beam 14 is formed, and then a-Si (polysilicon, other materials such as polyamide, etc. may be used) on the sacrifice layer 24 and the insulating film 15. Actuator layers 25, 2
6 is deposited and the movable and fixed parts are patterned.
Then, the sacrificial layer 24 is etched and the both-supported beam 14
Is a movable shape. Here, after dicing the Si substrate 11 into a chip shape, the semiconductor laser 12 having an antireflection coating 27 on one end face is bonded.

FIG. 3 is a schematic perspective view of a wavelength tunable semiconductor light emitting device according to another embodiment of the present invention.

As shown in FIG. 3, the wavelength tunable semiconductor light emitting device of this embodiment is of a monolithic type, and is a semiconductor insulating substrate (GaAs, InP) for forming a laser layer.
A semiconductor laser 32, a movable double-supported beam 34 on which an external mirror 33 forming a microactuator 49 is formed, and a fixed electrode 35 are monolithically formed on the substrate 31, and have a size of about 500 μm × 500 μm.

Such a wavelength tunable semiconductor laser device is
For example, it is manufactured as follows. First, after a layer serving as the lower conductive layer 36 of the semiconductor laser 32 is grown on the semiconductor insulating substrate 31, a normal semiconductor laser layer 37 is crystal-grown. Next, the movable double-supported beam 34, the fixed comb-shaped portion (electrode) 35, and the semiconductor laser 3 which constitute the actuator portion 49.
The second etched mirror 38 is patterned, and reactive dry etching is performed to a depth reaching the semiconductor insulating substrate 31. And Etched Mirror 3
After coating an antireflection film on the surface 8 by an oblique deposition method or the like, the surface for forming the lower electrode of the semiconductor laser 32 is exposed by etching. Further, the upper and lower electrode (P, N) pads 39, 40 of the semiconductor laser 32
And after forming the actuator electrode pads 41, 42,
The lower sacrificial layer of the doubly supported beam 34 is etched to cover the semiconductor laser 32, and finally the chip is divided by cleavage. The wavelength tunable semiconductor light emitting device of this embodiment has an advantage over the above-described one that the process of assembling the laser and the external mirror can be performed at once.

FIG. 4 is a plan view showing various patterns of the microactuator. 4A shows the simplest shape, in which a concave portion is formed on the substrate 41 on the side of the movable beam 42, and a convex portion that enters the concave portion is formed on the side of the fixed portion 43. Is. Incidentally, 44 is a semiconductor laser. In the structure shown in FIG. 4B, the movable beam 45 side and the fixed portion 46 side are respectively comb-shaped as described above in order to reduce the applied voltage.

Further, in the structure shown in FIG. 4 (c), fixed portions 48 and 49 are formed on both sides of the movable beam 47 and drive electrodes 50 and 50 are formed so that the movement of the movable beam can be further finely adjusted.
Since three 51 and 52 are formed, the movable beam 47 can be driven back and forth and a small amount of tilt can be adjusted. The shape of the driving unit is not limited to the above.

[0020]

As described above in detail with reference to the embodiments, according to the wavelength tunable semiconductor light emitting device of the present invention, the external mirror and the microactuator are formed on the substrate on which the semiconductor laser is mounted, or Further, since the semiconductor laser, the external mirror, and the microactuator are formed on the same substrate, it is not necessary to assemble the individual parts constituting the device,
The mass productivity and economic efficiency of the device can be greatly improved, and the actuator is very small, so high-speed drive is possible and high frequency operation of the device can be obtained. Moreover, the actuator drive power is low. Labor saving of the entire apparatus can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of a wavelength tunable semiconductor light emitting device according to an embodiment of the present invention.

FIG. 2 is a schematic view of a forming process showing a method of manufacturing a wavelength tunable semiconductor light emitting device.

FIG. 3 is a schematic perspective view of a wavelength tunable semiconductor light emitting device according to another embodiment of the present invention.

FIG. 4 is a plan view showing various patterns of a microactuator.

FIG. 5 is a schematic perspective view of a conventional wavelength tunable semiconductor light emitting device.

[Explanation of symbols]

11, 31 Substrate 12, 32 Semiconductor laser 13, 33 External mirror 14, 34 Movable beam 15 Insulating film 18, 35 Fixed comb-shaped portion 19, 49 Microactuator 20, 21, 22, 39, 40, 41, 42 Electrode pad

Claims (2)

[Claims] 1. A tunable semiconductor light emitting device having a semiconductor laser, an external mirror, and a microactuator for driving the external mirror in the optical axis direction of the semiconductor laser, wherein the external mirror and the microactuator are the semiconductor laser. A tunable semiconductor light emitting device, which is formed on a substrate on which is mounted. 2. A wavelength tunable semiconductor light emitting device having a semiconductor laser, an external mirror, and a microactuator for driving the external mirror in the optical axis direction of the semiconductor laser, wherein the semiconductor laser, the external mirror, and the microactuator are provided. A tunable semiconductor light emitting device characterized in that are formed on the same substrate.