Thermoelectric effect in quantum cascade lasers

Matthew D. Escarra, Alexander Benz, Anjali M. Bhatt, Anthony J. Hoffman, Xiaojun Wang, Jen Yu Fan, Claire F. Gmachl

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


The choice of polarity of operation in a quantum cascade (QC) laser is made at the beginning of every QC laser design and growth, yet little work has been done to ascertain any performance benefits of one polarity versus the other. In this paper, we compare two QC lasers of the same design, differentiated only by the reversing of the growth order of the heterostructure layers in the laser core, which results in opposite polarities of operation. Analysis is performed through continuous wave (CW) and pulsed threshold current measurements to observe the change in active core temperature with input power. A thermoelectric effect is observed, where the direction of current flow improves thermal transport in negative polarity lasers (electron flow toward the heat sink) over positive polarity (electron flow away from the heat sink), leading to a maximum observed reduction in laser core heating of 10.0 ± 5.5 K for a thermal load of 7.2 kW/cm2 in CW operation.

Original languageEnglish (US)
Article number5464343
Pages (from-to)500-509
Number of pages10
JournalIEEE Photonics Journal
Issue number3
StatePublished - 2010

All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering


  • Quantum cascade lasers
  • optoelectronic materials
  • superlattice devices
  • thermal modeling
  • thermoelectric effect


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