Pamela K. York

Ultralow‐loss broadened‐waveguide high‐power 2 μm AlGaAsSb/InGaAsSb/GaSb separate‐confinement quantum‐well lasers

Broadening the waveguides of 2 μm AlGaAsSb/InGaAsSb separate‐confinement multiquantum‐well lasers decreases their internal losses to 2 cm−1, while threshold current densities remain as low as 300 A/cm2. The consequently high cw differential efficiency of 0.36 results in output powers of 1.2 W from 100 μm aperture lasers at 15 °C.

4 W quasi-continuous-wave output power from 2 μm AlGaAsSb/InGaAsSb single-quantum-well broadened waveguide laser diodes

AlGaAsSb/InGaAsSb single-quantum-well (SQW) laser diodes emitting at 2 μm were fabricated and tested. At 10–15 °C, the uncoated SQW lasers with 2–3 mm cavity lengths exhibit a threshold current density of 115 A/cm2, a continuous-wave output power of 1.9 W, a differential efficiency of 53%, and a quasi-continuous-wave output power of 4 W. Their performance deteriorates rapidly as output losses increase beyond 10 cm−1.

Room‐temperature 2.78 μm AlGaAsSb/InGaAsSb quantum‐well lasers

We describe room‐temperature 2.78 μm AlGaAsSb/InGaAsSb multiquantum well lasers. Pulsed laser operation was observed at 15 °C with a threshold current of 1.1 A (10 kA/cm2), and a maximum power output of 30 mW, and a maximum differential quantum efficiency of 9%. Lasers operated pulsed up to 60 °C with a characteristic temperature of 58 K over the range of 0–40 °C. To date, 2.78 μm is the longest emission wavelength for a room‐temperature III–V laser.

3.06 μm InGaAsSb/InPSb diode lasers grown by organometallic vapor‐phase epitaxy

We have observed laser action at λ=3.06 μm in In0.77Ga0.23As0.74Sb0.26/InP0.7Sb0.3 double heterojunction, diode lasers, which were grown by organometallic vapor‐phase epitaxy. The maximum operating temperature was T=35 K, and typical threshold current densities were 200–330 A/cm2. At temperatures up to 35 K, the lasing wavelength decreased with increasing temperature owing to a band‐filling effect.

2.7‐μm InGaAsSb/AlGaAsSb laser diodes with continuous‐wave operation up to −39 °C

We have demonstrated continuous wave operation of 2.7‐μm InGaAsSb/AlGaAsSb multiquantum‐well diode lasers up to a temperature of 234 K (−39 °C). These devices were grown by molecular‐beam‐epitaxy. They have a tendency to operate in a dominant single mode over well‐defined temperature and current intervals. A comparison of spontaneous emission spectra shows that above threshold, the quasi‐Fermi level is pinned and that most of the carriers are injected into nonlasing states. This effect leads to a rapid decrease of differential efficiency with increasing temperature.

Low-Loss, Broadened-Waveguide, High-Power 2-μm AlGaAsSb/InGaAsSb/GaSb Separate Confinement Quantum-Well Lasers

(Al, In)GaAsSb/GaSb MQW lasers with a broadened waveguide have been used to fabricate 2-μm diode lasers with CW output power of 1.2 W. 2-μm linear arrays have output powers of 11 W and an efficiency of 0.13 W/A.

Mid-infrared III-V diode lasers for trace-gas sensing

Semiconductor diode lasers are well-suited as sources for trace-gas monitoring systems using laser absorption spectroscopy (LAS). They are compact, and as single-mode, distributed feedback (DFB) lasers, their wavelengths tune continuously and accurately with current and temperature. In the near-infrared from about 1.25 to 2 /spl mu/m, diode lasers with wavelengths corresponding to the molecular absorption lines are commercially available.

2.7-μm InGaAsSb/AlGaAsSb laser diodes with continuous wave operation up to -39°c

Continuous and quasi-continuous wave operation of 2.7-μ InGaAsSb/AlGaAsSb multi-quantum-well (MQW) lasers was demonstrated up to a temperature of 234 K (-39°C) and 253 K (-20°C), respectively. These devices were grown by molecular-beam epitaxy (MBE). They tend to operate in a dominant single mode over well defined temperature and current intervals. A comparison of spontaneous emission spectra shows that above threshold the quasi-Fermi level is pinned and that most of the carriers are injected into non-lasing states. This effect leads to a rapid decrease of differential efficiency with increasing temperature.

3-μ InGaAsSb/InPSb diode lasers grown by organometallic vapor-phase epitaxy

We have observed laser action in InO7GaO3AsO72SbO28 IInPO.7SbO.3 double heterojunction, diode lasers at ? = 3.06 .tm. The maximum operating temperature was 35 K. The threshold current densities were in the range of 200 - 330 A /cm These devices were grown by organometallic vapor-phase epitaxy.