We present laser results of OPS structures based on highly strained InGaAs quantum wells emitting at 1178nm and
frequency doubled to produce high power, high beam quality laser radiation at 589nm. The laser architecture is the same
as in our commercial offerings, allowing us to achieve the desired results with a system significantly simpler than
Optically-pumped semiconductor (OPS) lasers are power-scalable, wavelength-flexible, infrared brightness converters.
Adding intra-cavity frequency doubling turns them into efficient, low noise, high power visible laser sources. We report
on a laser combining an InGaAs gain medium with an LBO nonlinear crystal to produce more than 20 Watt CW in
single transverse mode at 532 nm. Efficient cooling of the single gain chip using advanced mounting techniques is the
key to making the laser reliable at high CW powers. A rugged and compact package withstands significant
environmental excursions. The laser's low noise makes it suitable for demanding Ti:Sapphire pumping applications.
Optically-pumped semiconductor lasers provide efficient laser sources in the ultraviolet by intra-cavity nonlinear
frequency tripling. A laser combining InGaAs gain media with LBO nonlinear crystals produces hundreds of mW CW at
355 nm. A compact package that combines thermal and opto-mechanical stability is the key to making this laser robust
and manufacturable. A temperature controlled, monolithic aluminum base supports opto-mechanical mounts made from
low expansion alloys and ceramics to create a resonator that can withstand substantial environmental excursions.
A microscopic interpretation of spontaneous and stimulated emission in semiconductor microcavities is developed using Semiconductor Luminescence Equations obtained from a quantum theory for the interacting electron-hole system and microcavity photons. The properties of bare quantum well luminescence as well as nonlinear photoluminescence of microcavity systems showing a threshold-like transition are consistently explained.
The threshold-like growth of the higher energy photoluminescence from a normal-mode-coupling microcavity was previously attributed to exciton polariton lasing (boser) based on Bose condensation into the upper polariton branch. Experimental evidence is presented here showing that this boser crossover occurs just as normal-mode coupling collapses to the perturbative weak coupling, so that boser action is fermionic after all. I.e., it can be understood as electron-hole recombination within a microcavity with density-dependent emission properties.