US 5,245,622 A · Vertical-cavity surface-emitting lasers with intra-cavity structures

Abstract

Vertical-cavity surface-emitting lasers (VCSELs) are disclosed having various intra-cavity structures to achieve low series resistance, high power efficiencies, and TEM.sub.00 mode radiation. In one embodiment of the invention, a VCSEL comprises a laser cavity disposed between an upper and a lower mirror. The laser cavity comprises upper and lower spacer layers sandwiching an active region. A stratified electrode for conducting electrical current to the active region is disposed between the upper mirror and the upper spacer. The stratified electrode comprises a plurality of alternating high and low doped layers for achieving low series resistance without increasing the optical absorption. The VCSEL further comprises a current aperture as a disk shaped region formed in the stratified electrode for suppressing higher mode radiation. The current aperture is formed by reducing or eliminating the conductivity of the annular surrounding regions. In another embodiment, a metal contact layer having an optical aperture is formed within the upper mirror of the VCSEL. The optical aperture blocks the optical field in such a manner that it eliminates higher transverse mode lasing.

Claims38

Dependent claims

A vertical-cavity surface-emitting laser that emits radiation at a wavelength, .lambda., comprising:

first and second mirrors defining therebetween an optical cavity;
an active region disposed between said first and second mirrors;
and
a first stratified electrode disposed substantially between said active layer and said first mirror, said first stratified electrode comprising a plurality of alternating high and low doped layers having a first conductivity type for injecting current into said active region to cause lasing, thereby establishing a standing wave in said cavity.

1 more element

A vertical-cavity surface-emitting semiconductor quantum well laser comprising:

a substrate;
a first mirror formed on said substrate;
a first spacer formed on said first mirror;
an active layer comprising at least one quantum well layer formed on said first spacer, said active layer emitting radiation at a wavelength .lambda.;
a second spacer formed on said active layer;
a stratified electrode formed on said active layer, comprising a plurality of alternating high and low doped layers of the same conductivity type as said second spacer for conducting current to said active layer to cause lasing;
and
a second mirror formed on said stratified electrode, said first and second mirrors defining therebetween a laser cavity having a length equal to m.lambda./2n.sub.eff, where m is an integer and n.sub.eff is the effective index of refraction of the cavity, wherein a standing wave is established, and said low and high doped layers are positioned approximately at the standing wave intensity maxima and minima, respectively, so as to reduce radiation absorption.

5 more elements

Dependencies are inferred from the claim text.

Vertical-cavity surface-emitting lasers with intra-cavity structures

Life of this patent

Vertical-cavity surface-emitting lasers with intra-cavity structures

Life of this patent

Abstract

Claims38