Experimental and Theoretical Study of the Temperature Performance of Type-II Quantum Well Lasers

Abstract

Abstract : The method of analyzing the temperature performance of type-II Interband Cascade (IC) GaSb-based semiconductor lasers has been developed. The method includes comparing the temperature-concentration dependence at the laser threshold with steady-state carrier heating characteristics. The number of cascades in prototype type-II IC lasers has been optimized with respect to the highest achievable operating temperature. An ultra-sensitive single-pass measurement technique was developed to study optical absorption in thin-layered laser heterostructures. The presence of strong non-radiative recombination in type-II laser structures was demonstrated by our measurement technique. We show that thermally induced hole escape from the active quantum wells is responsible for deterioration of the optical emission both in type-I and type-II laser structures at elevated temperatures. New method of laser temperature characterization has been developed and tested on high-power diode arrays, which are especially vulnerable to heat generation and kinetics. The study of type-II IC laser structures resulted in a proposal of a novel electrically tunable mid-IR light source. We have designed and experimentally demonstrated a working prototype of multimode electrically tunable IC laser operating in mid-infrared spectral region. The device demonstrates ultra-wide wavelength tuning in the range of up to 120 nm.