US 5,412,680 A · Linear polarization of semiconductor laser

Abstract

This invention discloses vertical cavity surface emitting lasers (VCSELs) formed to emit optical radiation that has a controlled direction of polarization. In one embodiment, a VCSEL has an active region that contains at least one strained semiconductor layer which has a preferred direction of electrical conductivity due to the strain. As a result, the optical radiation emitted from the VCSEL has a direction of polarization that is parallel to the preferred direction of conductivity. In another embodiment, a VCSEL has an elongated active region, and the direction of polarization of the radiation emitted from the VCSEL is parallel to a longitudinal axis of the active region. The invention also discloses a VCSEL array comprising vertical cavity surface emitting lasers having elongated active regions. By forming the elongated active regions parallel to each other, the array emits optical radiation having parallel polarization. Alternatively, the array may be formed so that the elongated active regions of adjacent VCSELs of the array are perpendicular to each other. As a result, adjacent VCSELs in the array emit optical radiation having orthogonal polarizations.

Claims19

Dependent claims

A vertical cavity surface emitting laser emitting optical radiation at a wavelength, .lambda., comprising:

first and second parallel mirrors forming therebetween an optical cavity;
and
an active region disposed between the mirrors, the active region comprising at least one strained semiconductor layer, the strained semiconductor layer having a preferred direction of electrical conductivity substantially along a first direction parallel to the mirrors, and said laser emitting optical radiation having a polarization substantially parallel to this first direction.

Dependencies are inferred from the claim text.

Linear polarization of semiconductor laser

Life of this patent

Linear polarization of semiconductor laser

Life of this patent

Abstract

Claims19