Multi-Color Quantum Cascade Mid-IR Sources at 2.5 to 5 um
Small Business Information
APPLIED OPTOELECTRONICS, INC.
242 King Fisher Drive, Sugarland, TX, 77478
AbstractA compact mid-IR dual wavelength laser is highly' desirable for the environmental gas and pollutant sensing, such as differential absorption lidar, where the light scattering has to be evaluated and compared at two different wavelengths. In the phase-Iproject, we have demonstrated the first two-color type-II interband-cascade (IC) laser in the world. It shows two lasing wavelengths at 4.482 and 4.568 um. The operation of single frequency mode was maintained with an output power > 8 mW. At 110 K, thedevices demonstrate a peak output power of 150 mW per facet with an average external quantum efficiency (EQE) of 278 percent with a pulse length of 5 psec and a frequency of 1 kHz. The EQE is at least two times better than any Sb-based lasers in the world,and is comparable with the best InGaAs InAlAs type-I QC lasers. In this project. we will further improve the material quality, laser design, processing, and packaging to reduce the leakage current, operating voltage, internal loss, and thermal impedance,and hence to improve the power efficiency and maximum operating temperature. It is expected that with these improvements with good AR HR facet coatings and adequate heat sink, we will be able to deliver packaged two-color type-II QC lasers with a cw outputpower > 10 mW at temperatures > 230 K adequate for many LIDAR and DIAL applications, or with a cw output power> 2 W at low temperature adequate for IR countermeasure and other military applications. Critical military needs include laser targetdesignators, IR countermeasures, remote chemical sensing for defense against biological chemical warfare, eye-safe covert illumination, and free-space communications. Commercial markets include leak detection, chemical process control, remote chemicalsensing for atmospheric pollution and drug monitoring, IR spectroscopy, and medical analyses. With the development of TE cooled two-colored Mid-IR lasers, this program should considerably accelerate the commercialization of mid-IR lasers to meet thepotential needs of the huge defense and commercial market.
* information listed above is at the time of submission.