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Lehigh University logo

Sushil Kumar

Department: Electrical and Computer Engineering

Position: Associate Professor

Address: Sinclair Lab 226
7 Asa Drive
Bethlehem, PA 18015
(610) 758-2606

E-mail: sushil@lehigh.edu

Research: Google Scholar

Areas of Research

  • Semiconductor Lasers
  • Quantum Cascade Lasers
  • Compound Semiconductor Technologies
  • Quantum Electronics
  • Silicon Photonics
  • Terahertz Technologies
  • Optics and Photonics


Sushil Kumar pursues research in far-infrared (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 and InPbased 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, Applied Physics Letters, Optics Express, and Physical Review. He seeks to also develop devices and systems 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, and 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 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, Nature Publishing Group, Optical Society of America, and IEEE, among others.


  • Ph.D., Electrical Engineering, Massachusetts Institute of Technology
  • M.S., Electrical Engineering, University of Michigan
  • B.S., Electronics and Communications, Delhi College of Engineering (India)