EAGER: Active Modelocking of Quantum Cascade Lasers

University Of Maryland Baltimore County, Baltimore MD

Investigators

Abstract

Intellectual Merit: There are currently no compact, short-pulse (< 10 ps) mid-IR laser sources. The proposed research will investigate the suppression of spatial hole burning as a means to achieve a self-starting, short-pulse quantum cascade laser (QCL) source. The PI will analyze the parameter range that would achieve stable operation, based on a conceptual gain structure. This simulation will yield a deeper understanding of the physics of coherence in such engineered structures. Preliminary concepts of the structure, derived from earlier concepts that achieved pulsing, but that could not self-start, were recently developed by the PI. The device would be based on the concept of interleaved gain and quantum coherent absorbing periods, which can be fabricated during controlled growth of the QCL laser structure. This interleaving should achieve suppression of deleterious continuous waves and favor stable pulsed operation. The quantum coherent absorption is expected to provide robust mode-locking of the laser source as drive parameters are varied. Broader Impact: This exploratory research will set the design space for a new pulsed QCL structure, which is a needed tool for multiple medical and sensing applications. Indeed many species of interest have strong spectral signatures in the mid infrared. This timely research will also be a good platform for student training. Additionally, this effort will leverage the NSF MIRTHE Center, centered in Princeton University, which develops QCLs and explores their applications; the MIRTHE center has the necessary equipment to experimentally verify the theoretical results obtained under this proposal.