Patent ID: 7606282

Claim:
A vertical cavity surface emitting laser (VCSEL), comprising: a bottom mirror above a substrate, the bottom mirror comprising a plurality of lower mirror pairs, each lower mirror pair comprised of a first bottom-mirror layer and a second bottom-mirror layer, the first and second bottom-mirror layers having different indices of refraction, wherein the first and second bottom-mirror layers have a contrast ratio that increases with increasing temperature over a desired operating temperature range; an active region above the bottom mirror, the active region comprising a plurality of quantum wells; and an upper mirror above the active region, the upper mirror comprising a plurality of upper mirror pairs, each upper mirror pair comprised of a first upper-mirror layer and a second upper-mirror layer, the first and second upper-mirror layers having different indices of refraction, wherein, with increasing temperature over the desired operating temperature range, the contrast ratio of the first and second upper-mirror layers either (i) decreases or (ii) increases to a lesser extent than the contrast ratio of the first and second bottom-mirror layers, thereby reducing fluctuation of a slope efficiency of the VCSEL; and wherein the VCSEL has an operating wavelength in a range from about 600 nm to about 870 nm and the bottom mirror comprises an Al x Ga x−1 As system, the first bottom-mirror layer having an aluminum content in a range from about 16 atomic % to about 25 atomic % and the second bottom-mirror layer having an aluminum content in a range from about 70 atomic % to about 100 atomic %.