Weimen Li ’17


Electrical Engineering

Project Title

Quantum Cascade Lasers and Detectors for Mid-Infrared Sensing of the Environment

Presentation Link

View Weimen's Presentation

My internship with the Mid-Infared Technologies for Health and Environment (MIRTHE) research group involved modeling and designing a waveguide for 16 μm quantum cascade lasers (QCLs). The primary purpose for the development of an infrared laser at this wavelength was to allow for sensing of trace gases in the environment, whose absorption spectra lies dominantly around λ=16 μm light. The work I did this summer consisted of using the COMSOL multiphysics software to design a waveguide for the laser. I also used MATLAB to implement models that can be used to help optimize waveguide designs. In the course of my work, I gained a rudimentary knowledge of photonic and semiconductor devices, and of how they are developed in research and used in industry. I also learned to program in MATLAB and use COMSOL multiphysics software, both of which are useful skills that may assist me in the future. Finally, I gained an interest in the field of semiconductor devices and photonics, which is a possible major track within the Department of Electrical Engineering here at Princeton. In that regard, I have the opportunity to return to working in the same laboratory for any junior or senior independent work, or thesis, if I so wish.

Internship Year


Project Category



Mid-Infared Technologies for Health and Environment (MIRTHE), Princeton University, Princeton, NJ


Claire Gmachl, Professor, Electrical Engineering