JP2555317Y2 - Surface emitting laser device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface emitting laser device provided with a vertical cavity surface emitting laser configured to take a direction perpendicular to a substrate as a resonance direction and to take out light output in this direction. In particular, the present invention relates to a surface emitting laser device that combines such a vertical cavity surface emitting laser and a linearly polarizing element to obtain a stable output laser beam.

[0002]

2. Description of the Related Art With the demand for higher integration of electronic devices, vertical cavity surface emitting lasers have been developed in which a direction perpendicular to a substrate is set as a resonance direction and light is output in this direction. In such a vertical cavity surface emitting laser, a resonator is constituted by an epitaxial surface epitaxially grown on a substrate and an end face of the substrate, and emits laser light in a direction perpendicular to the substrate surface (epitaxial growth direction).

[0003]

In such vertical cavity surface emitting lasers developed so far, none of the laser light emitted is controlled in the direction of polarization. There is a problem that the output of the laser beam may become unstable due to the qualitative property. Especially,
When forming a two-dimensional laser array using a plurality of vertical cavity surface emitting lasers, it is necessary to align the deflection directions of the vertical cavity surface emitting lasers, and the polarization of each vertical cavity surface emitting laser is required. Directional instability is an important issue to be solved.

The present invention has been made in view of such circumstances, and provides a surface emitting laser device capable of obtaining a stable output laser beam by providing a linearly polarizing element on the laser beam output side. With the goal.

[0005]

The surface emitting laser device according to the present invention comprises a linear polarization element on the laser light emitting side of a vertical cavity surface emitting laser manufactured by growing a semiconductor material on a substrate. A surface emitting laser device arranged, wherein the linearly polarizing element is arranged in a direction inclined approximately 45 degrees from a [011] axis direction of crystal growth in the surface emitting laser to a [0-11] axis direction. I do.

[0006]

The normal polarization direction of a vertical cavity surface emitting laser is the [011] axis direction of crystal growth. In the case of a vertical cavity surface emitting laser whose polarization direction is unstable, the normal polarization direction is [0]. -11] A polarization component in the axial direction is generated. In the surface emitting laser device of the present invention, the linearly polarizing element is arranged in a direction inclined by 45 degrees in the [0-11] axis direction from the [011] axis direction of crystal growth. Then, the laser light transmitted through the linearly polarizing element has the [011] polarization component and the [0-
11] Having a polarization component at the same time, a stable output laser beam can be obtained.

[0007]

Next, an embodiment of the present invention will be described. FIG. 1 is a schematic diagram showing the configuration of the surface emitting laser device according to the present invention. In FIG. 1, reference numeral 1 denotes a vertical cavity surface emitting laser, and this surface emitting laser 1 has a buried structure of a GaAs active layer and emits laser light from the wafer surface.
This is a GaAs active layer buried wafer surface light emission type surface emitting laser. On the emission side of the laser light of the surface emitting laser 1, a polarization beam splitter 2, which is a linearly polarizing element, is provided with a [0−
11] It is arranged in a direction inclined by 45 degrees in the axial direction.

Next, the operation will be described. FIG. 2 is a schematic view showing the operation principle of the surface emitting laser device of the present invention. In the region where the laser light is stable, the polarization direction of the surface emitting laser 1 is usually in the [011] axis direction (A in FIG. 2).
Direction). On the other hand, in a region where the laser beam is unstable, the polarization direction is switched between the [011] axis direction and the [0-11] axis direction (the B direction in FIG. 2). In the present invention, since the polarization beam splitter 2 is disposed in a direction inclined by 45 degrees from the [011] axis direction to the [0-11] axis direction, the polarization direction of the laser beam transmitted through the polarization beam splitter 2 Is [0-1] from the [011] axis direction regardless of whether the polarization direction of the input light is the [011] axis direction (A direction) or the [0-11] axis direction (B direction).
1] A direction inclined by 45 degrees in the axial direction (direction C in FIG. 2). As a result, even if the polarization direction of the laser light emitted from the surface emitting laser 1 is unstable, the polarization direction of the laser light transmitted through the polarization beam splitter 2 is stable, and a stable output laser light can be obtained. It is possible.

[0009]

As described above, in the surface emitting laser device of the present invention, the laser light emission side of the vertical cavity surface emitting laser is shifted from the [011] axis direction of crystal growth to the [0-11] axis direction. Since the linear polarization element is arranged in a direction inclined by approximately 45 degrees, a laser beam having stable linear polarization can be obtained. Further, when a two-dimensional array is formed using the surface emitting laser device of the present invention, the polarization directions of the vertical cavity surface emitting lasers serving as the light emitting elements can be aligned.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a surface emitting laser device according to the present invention.

FIG. 2 is a schematic view showing the operation principle of the surface emitting laser device of the present invention.

[Explanation of symbols]

 1 surface emitting laser 2 polarization beam splitter

Claims (1)

(57) [Scope of request for utility model registration] 1. A vertical cavity surface emitting laser produced by growing a semiconductor substance on a substrate by crystal growth, wherein a surface-emitting laser device is provided with a linearly polarizing element on a laser beam emission side. Wherein the linearly polarizing element is arranged in a direction inclined at approximately 45 degrees in the [0-11] axis direction from the [011] axis direction of the crystal growth in [1].