We are developing new classes of infrared (IR) lasers and detectors capable of enhanced performance, with emphasis on wavelengths in the range 3-25 μm. These lasers include type-II antimonide interband cascade lasers, “W” lasers, quantum cascade lasers, mid-IR vertical-cavity surface-emitting lasers, distributed feedback lasers, photonic crystal distributed feedback lasers, and plasmonic lasers. Detailed band structure, optical, and transport simulations are used to optimize the device designs prior to growth and fabrication of each laser structure. High quality growth is done on GaSb and InP substrates in two in-house molecular beam epitaxy systems. Device processing includes e-beam and optical lightography, reactive ion and wet chemical etching, facet coating, sputtering, thermal evaporation, e-beam deposition, gold electro-plating, and epitaxial-side-down mounting. Laser characterization facilities include pulsed and cw optical pumping sources at a variety of wavelengths, pulse generators, IR detectors and spectrometers, FTIR, IR cameras signal averagers, beam analyzers, and dedicated computers for full automation of the data acquisition. Fundamental properties of laser materials are studied, including QW band structure, Auger recombination rate, internal loss and efficiency, linewidth enhancement factor, optical mode properties, far-field profiling, and thermal transport. Primary research objectives are to develop mid-IR laser sources that produce high cw output powers and/or single mode spectral purity at ambient or thermoelectric-cooler temperatures, and IR detectors with high dynamic resistance-area products. NRL interband cascade lasers are now the leading low-input-power semiconductor sources for wavelengths in the 3-5 micron spectral band.

 

key words

Diode laser; Infrared detector; Interband cascade laser; Mid-IR; Molecular beam epitaxy; Photonic crystal laser; Quantum cascade laser; Type-II quantum well; W laser;

Citizenship:  Open to U.S. citizens and permanent residents

Level:  Open to Postdoctoral applicants