The analysis of I-V and I-L curves in mid-IR quantum cascade lasers operating at room temperature is performed. When the ohmic component of the device resistance in the I-V curve is subtracted, the current I can be approximated by the exponential function, I = I_s exp(eV_j/ε) where I_s is the saturation current, Vj is the n-n junction voltage, and ε is an energy parameter related to the tunneling mechanism which enables filling of upper states and emptying of lower states of the laser transition. Values of εare found to be in 0.68-1.45 eV range, and when divided by the number of stages in the cascade, the tunneling parameter of each stage is determined. The threshold related “kink” of differential I-V curves is shown. The effect of voltage saturation above the laser threshold is observed. Thus, the possibility of determination of the threshold using electrical measurements in quantum cascade lasers has been demonstrated.

Date Published: 10 March 2015
PDF: 6 pages
Proc. SPIE 9382, Novel In-Plane Semiconductor Lasers XIV, 93821R (10 March 2015); doi: 10.1117/12.2076663

Published in SPIE Proceedings Vol. 9382:
Novel In-Plane Semiconductor Lasers XIV
Alexey A. Belyanin; Peter M. Smowton, Editor(s)