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We demonstrated a wide CW wavelength tuning range of 18 cm-1 for an epi-up mounted distributed feedback (DFB) quantum cascade laser (QCL) around 4.5 m, via current change. The wavelength tuning coefficient of an epi-up mounted DFB QCL is about 2.2 times of that of an epi-down mounted one. The 3dB modulation bandwidths of an epi-up and an epi-down mounted DFB QCLs are 15 kHz and 400 kHz, respectively.

We demonstrated room temperature CW operation of DFB quantum cascade lasers with wide wavelength coverage from 4.83 μm to 5.44 μm, corresponding to a wavenumber coverage of 232 cm−1, for NO x sensing applications.

We report highly reliable 1060-nm DBR semiconductor lasers after aging the gain section and DBR-section heater for up to 24000 and 11000 hrs, respectively, at various high-stress conditions.

We fabricated 1060-nm DBR lasers with 480-mW output power and integrated micro heaters. A 20-nm discrete wavelength tuning using Bragg-section heater alone and a 1-nm continuous tuning using both Bragg- and phase-section heaters are demonstrated.

We report highly reliable 1060-nm DBR lasers with a single-wavelength output power larger than 350 mW and a failure rate as low as 3.2 kFITs at a heat-sink temperature of 25degC and a gain current of 500 mA. The reliability data of the high-power 1060-nm DBR lasers under longest aging tests at the highest level of current and temperature stress have been obtained for the first time, to the best of our knowledge

High power broad area semiconductor lasers have found increasing applications in pumping of solid state laser systems and fiber amplifiers, frequency doubling, medical systems and material processing. Packaging including the assembly design, process and thermal management, has a significant impact on the optical performance and reliability of a high power broad area laser. In this paper, we introduce the package structures and assembling process of 980nm broad area lasers and report the performances including output power, thermal behavior and far fields. We will report two types of high power broad area laser assemblies. One is a microchannel liquid cooled assembly and the other is a conduction cooled CT-mount assembly. Optical powers of 15W and 10W were achieved from a 980nm broad area laser with a 120 m stripe width in a microchannel liquid cooled assembly and conduction cooled CT-mount assembly, respectively. Furthermore, a high power of 6.5W out of fiber was demonstrated from a pigtailed, fully packaged butterfly-type module without TEC (thermoelectric cooler). The measurement results showed that thermal management is the key in not only improving output power, but also significantly improving beam divergence and far field distribution. The results also showed that the die attach solder can significant impact the reliability of high power broad area lasers and that indium solder is not suitable for high power laser applications due to electromigration at high current densities and high temperatures.