Non-linear dynamics modeling of quantum cascade lasers with tilted optical feedback

Abstract

Semiconductor lasers subject to optical feedback usually produce rich nonlinear dynamics, including periodic oscillations, quasi-periodic oscillations, and chaotic oscillations. However, quantum cascade lasers (QCLs) are highly stable against normal optical feedback, owing to the intersubband transition with ultrashort carrier lifetime and the near zero linewidth broadening factor. This work numerically shows that tilted optical feedback from a misaligned reflection mirror triggers the generation of nonlinear dynamics from QCLs, which is in good agreement with our previous experimental observations. The physical mechanism is attributed to the non-degeneration of the odd-order round-trip feedback path with the even-order ones.