A widely voltage-tunable quantum cascade laser based on “two-step” coupling

Abstract

A novel quantum cascade laser design with “two-step” coupling between the injector and the upper laser state is demonstrated to achieve a widely voltage-tunable laser spectrum. Electroluminescence from this design can be tuned over a range of more than 200 cm−1 with a tuning coefficient of ∼700 cm−1/V per stage. Lasers based on this design provide a tuning range of ∼100 cm−1 (8.3–9 μm) above threshold with a tuning coefficient of ∼900 cm−1/V per stage at a constant temperature of 295 K.