Sushil Kumar pursues research in terahertz and mid-infrared photonics with quantum-cascade lasers and detectors and nanostructured intersubband semiconductor devices. Currently, he is engaged in projects to develop optoelectronic devices (both light emitters and detectors) based on semiconductor heterostructures in GaAs, InP, and GaN based material systems, which operate at far-infrared and mid-infrared frequencies.
Sushil's work is at the forefront of terahertz semiconductor 'quantum-cascade' laser technology, and has posted world-record results for high-temperature and high-power operation of such lasers. He has published his research in journals such as Nature Physics, Nature Photonics, Physical Review, and Applied Physics Letters. He seeks to also develop devices that target potential applications in chemical and biological sensing, spectroscopy, and imaging such as sensing for detection of explosives and drugs in packaging, imaging for disease diagnosis, quality control in pharmaceutical industry, remote-sensing in astronomy to understand star and galaxy formation among many others.
Kumar performed his Ph.D. research and postdoctoral training at the Massachusetts Institute of Technology in the field of semiconductor lasers operating in the terahertz (far-infrared) region of the electromagnetic spectrum. He has varied interests in teaching of both graduate and undergraduate level courses on the topics of fundamentals of semiconducor devices, optoelectronics, and solid-state physics. He is a reviewer of journals published by the American Institute of Physics, Optical Society of America, and IEEE, among others.
Compound Semiconductor Technologies
Optics and Photonics
Quantum Cascade Lasers