Transverse mode control in quantum cascade lasers via lossy lateral constrictions

Pierre M. Bouzi, Peter Q. Liu, Nyan Aung, Xiaojun Wang, Jen Yu Fan, Mariano Troccoli, Claire F. Gmachl

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations


Quantum Cascade (QC) lasers are semiconductor devices operating in the mid-infrared and terahertz regions of the electromagnetic spectrum. Since their first demonstration in 1994, they have evolved rapidly into high power devices. However, they also have intrinsic challenges, such as beam steering at high power. Such phenomenon has been observed in QC lasers and attributed to the interaction between the two lowest transverse modes in the laser cavity. In this project, we have used COMSOL Multiphysics simulations to first investigate how transverse mode propagation can be controlled with cavity spoilers. We have modeled this effect by creating short and lossy lateral constrictions from the top of the laser ridge to perturb the modes distributed more toward the sides of the laser ridge, while leaving the fundamental mode intact. After obtaining optimized dimensions for the constrictions, we have utilized focused ion beam (FIB) milling to etch two small trenches from the top of several laser ridges to create the simulated effect on our devices. We, then, filled them with platinum in an effort to completely suppress the propagation of higher order transverse modes in the cavity. The results obtained show minimal effect on threshold and a Gaussian far-field distribution at various current levels, indicating a complete suppression of the higher order transverse modes.

Original languageEnglish (US)
Title of host publicationNovel In-Plane Semiconductor Lasers XII
StatePublished - 2013
EventNovel In-Plane Semiconductor Lasers XII - San Francisco, CA, United States
Duration: Feb 4 2013Feb 7 2013

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherNovel In-Plane Semiconductor Lasers XII
Country/TerritoryUnited States
CitySan Francisco, CA

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Applied Mathematics
  • Electrical and Electronic Engineering
  • Computer Science Applications


  • Constriction
  • Quantum Cascade lasers
  • Transverse mode control


Dive into the research topics of 'Transverse mode control in quantum cascade lasers via lossy lateral constrictions'. Together they form a unique fingerprint.

Cite this