TY - JOUR
T1 - Thermoelectric effect in quantum cascade lasers
AU - Escarra, Matthew D.
AU - Benz, Alexander
AU - Bhatt, Anjali M.
AU - Hoffman, Anthony J.
AU - Wang, Xiaojun
AU - Fan, Jen Yu
AU - Gmachl, Claire F.
N1 - Funding Information:
Manuscript received March 29, 2010; revised May 6, 2010; accepted May 6, 2010. Date of publication May 12, 2010; date of current version June 11, 2010. This work was supported in part by DARPA-EMIL, by MIRTHE (NSF-ERC #EEC-0540832), and by REU Site: I-MIRTHE REU (#EEC-0648721). Corresponding author: M. D. Escarra (e-mail: [email protected]).
PY - 2010
Y1 - 2010
N2 - 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.
AB - 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.
KW - Quantum cascade lasers
KW - optoelectronic materials
KW - superlattice devices
KW - thermal modeling
KW - thermoelectric effect
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U2 - 10.1109/JPHOT.2010.2050304
DO - 10.1109/JPHOT.2010.2050304
M3 - Article
AN - SCOPUS:84858795239
SN - 1943-0655
VL - 2
SP - 500
EP - 509
JO - IEEE Photonics Journal
JF - IEEE Photonics Journal
IS - 3
M1 - 5464343
ER -