Broadband quantum cascade laser gain medium based on a “continuum-to-bound” active region design

摘要

We present quantum cascade laser designs at 7–9 u0002m with two lower injector states stronglyncoupled with the upper laser state at the operating electric fields. Optical transitions from these threencoupled states contribute to a large gain spectrum width u0002u0004250 cm−1nfull width at half maximumu0003,nwhich enables external cavity tuning of the lasers over 200 cm−1n. Lasers show comparablenperformance to the conventional narrow band design at a similar wavelength with a peak modalngain coefficient of u000410 kA/cm, a slope efficiency u00041W/A, and good temperature performancenu0002T0 =170 Ku0003 in pulsed mode operation at 295 K. © 2010 American Institute of Physics.nu0005doi:10.1063/1.3431577