JPH04343285A - Semiconductor laser device - Google Patents

Abstract

PURPOSE:To enable a semiconductor laser device to be lessened in size and weight. CONSTITUTION:Laser rays emitted from a semiconductor laser 1 are made to impinge on a lens 4. The lens 4 is possessed of a curved surface, so that it converts the incident laser rays into convergent rays in parallel with a semiconductor substrate. The lens 4 has a distribution of refractive indexes in the thicknesswise direction, but it has a small aperture, so that it can be focused outside of a laser ray projecting window 3. Therefore, laser rays diverging from the lens 4 are converted into parallel laser rays vertical to the semiconductor substrate once, and then the parallel laser rays are converted into convergent rays through the curvature of the laser projecting window 3 in the direction vertical to the semiconductor substrate. By this setup, as mentioned above, when the projected light rays from a semiconductor laser device are effectively used, the light rays can be outputted as convergent rays or parallel rays without using an additional lens, and thus the device concerned can be lessened in size and weight and enlarged in application for various fields.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser device which is an inexpensive, high performance, and highly efficient light source used in the optical industry.

0002

2. Description of the Related Art FIG. 4 is a diagram illustrating a conventional semiconductor laser device. In conventional semiconductor laser devices, the diameter of the emitted beam from the semiconductor laser is very small, several micrometers or less, so the beam diameter diverges at an angle of several tens of degrees due to diffraction. Therefore, in order to effectively utilize the light emitted from the semiconductor laser, a separate lens is required to convert the light into parallel light or focused light.

0003

[Problem to be Solved by the Invention] Conventional semiconductor laser devices use another lens to effectively utilize the light emitted from the semiconductor laser, so there is a problem in that they are not suitable for reducing the size and weight of the device. there were. Therefore, an object of the present invention is to solve the problem that light emitted from a semiconductor laser diverges at an angle of several tens of degrees, and to provide a semiconductor laser that can emit parallel light or focused light.

0004

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a lens section on a semiconductor substrate constituting a semiconductor laser section with a refractive index distribution in the film thickness direction, or In addition to giving it a curved shape in the parallel direction, the laser beam exit window attached to the container should have a refractive index distribution in the direction perpendicular to the semiconductor substrate.
Alternatively, it may have a curved shape in this direction.

[0005]

[Operation] Diverging light emitted from a semiconductor laser is converted into parallel light or convergent light by a lens made of a distributed refractive index film provided on a semiconductor substrate and a lens provided in a laser beam exit window.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of a semiconductor laser device according to the present invention. This semiconductor laser device is a semiconductor laser device that emits focused light. In the figure, laser light emitted from a semiconductor laser section 1 attached to a container 2 enters a lens section 4. This lens portion 4 has a curved shape as shown in the top view of (b),
This converts the diverging laser light into focused light in a direction parallel to the semiconductor laser substrate. Moreover, this lens section 4 is
As shown in the side view of (a), it has a refractive index distribution in the film thickness direction. However, since the lens portion 4 is made of a thin film, the aperture is small, and the focal length cannot be set to about the square of the film thickness. Therefore, in order to focus the laser beam outside the laser beam emission window 3, the laser beam diverging by the lens portion 4 is once converted into parallel light in a direction perpendicular to the semiconductor laser substrate. The laser beam that has passed through the lens section 4 enters the laser beam exit window 3 and is converted into a focused beam by the curvature in the direction perpendicular to the semiconductor laser substrate.

FIG. 2 shows the second structure of the semiconductor laser device of the present invention.
1 is a configuration diagram showing an embodiment of the present invention, which is a semiconductor laser device that emits laser light that is focused in a direction parallel to a semiconductor laser substrate and parallel in a perpendicular direction. Laser light emitted from the semiconductor laser section 1 attached to the container 2 enters the lens section 4 . This lens section 4 has a curved shape as shown in the top view of (b), and thereby converts diverging laser light into focused light in a direction parallel to the semiconductor laser substrate. Further, as shown in the side view of (a), this lens portion 4 has a refractive index distribution in the film thickness direction, thereby converting the diverging laser light into a focused light in the direction perpendicular to the semiconductor laser substrate. Convert. However, since the lens portion 4 is made of a thin film and has a small aperture and a short focal length, the light becomes diverging light again. This diverging laser beam enters the laser beam exit window 3 and is converted into a wider parallel beam due to the curvature in the direction perpendicular to the semiconductor laser substrate.

FIG. 3 shows the third structure of the semiconductor laser device of the present invention.
1 is a configuration diagram showing an embodiment of the present invention, which is a semiconductor laser device that emits focused light. Laser light emitted from the semiconductor laser section 1 attached to the container 2 enters the lens section 4 . As shown in the top view of (b), this lens portion 4 is
It has a curved shape, thereby converting diverging laser light into focused light only in the direction parallel to the semiconductor laser substrate. Since the light does not function in the direction perpendicular to the semiconductor laser substrate, it remains a divergent light. This laser light enters the laser light exit window 3 and is converted into a focused light by the vertical curvature of the semiconductor laser substrate.

In the above embodiments, even if the laser beam exit window 3 is a distributed refractive index lens or a diffraction lens, it has the same function as described above. In addition, the semiconductor laser section 1
Since the emitted light from the laser beam is sufficiently wide in the horizontal direction and can be regarded as almost parallel light, the lens portion 4 does not have a curved shape in the direction parallel to the semiconductor substrate and has only a refractive index distribution in the vertical direction. There is also a configuration in which the light is converted into parallel light by the curvature of the light exit window 3 in the direction perpendicular to the substrate.

0010

[Effects of the Invention] As explained above, since the semiconductor laser device of the present invention emits parallel light or focused light, it does not require any other lens, and therefore the entire optical device can be significantly reduced in size and weight. can be achieved. Therefore, the scope of application of semiconductor lasers to optical sensors, optical communications, optical information processing, etc. is expanded, and industrial advantages are extremely large.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a semiconductor laser device according to the present invention, in which (a) is a cross-sectional view thereof, and (b) is a top view thereof.

FIG. 2 is a configuration diagram showing a second embodiment of the semiconductor laser device, in which (a) is a cross-sectional view thereof, and (b) is a top view thereof.

FIG. 3 is a configuration diagram showing a third embodiment of the semiconductor laser device, in which (a) is a cross-sectional view thereof, and (b) is a top view thereof.

FIG. 4 is a configuration diagram of a conventional semiconductor laser device.

[Explanation of symbols]

1 Semiconductor laser section 2 Container 3 Laser light exit window

Claims (1)

[Claims] 1. A semiconductor laser section consisting of a semiconductor substrate, an active layer, and a pair of cladding layers sandwiching the active layer, a lens section consisting of a transparent thin film formed on the semiconductor substrate, and a lens section for fixing and sealing the semiconductor substrate. In the semiconductor laser device, the lens portion has a refractive index distribution in a film thickness direction or a curved shape in a direction parallel to the semiconductor substrate. . A semiconductor laser device, wherein the laser beam exit window has a diagonal in a direction perpendicular to the semiconductor substrate.