Long wavelength quantum cascade lasers based on high strain composition

摘要

An improved longwave infrared quantum cascade laser. The improvement includes a strained InxGa1-xAs/AlyIn1-yAs composition, with x and y each between 0.53 and 1, an active region emitting at a wavelength equal to or greater than 8 μm, an energy spacing E54 equal to or greater than 50 meV, an energy spacing EC4 equal to or greater than 250 meV, and an optical waveguide with a cladding layer on each side of the active region. Each cladding layer has a doping level of about 2·1016 cm−3. The optical waveguide also has a top InP layer with a doping level of about 5·1016 cm−3 and a bottom InP layer with a doping level of about 5 1016 cm−3. Additionally, the optical waveguide has a plasmon layer with a doping level of about 8·1018 cm−3.

主权项

1. An improved longwave infrared quantum cascade laser, the improvement comprising:
(a) a highly strained In0.5840Ga0.4160As/Al0.6417In0.3583As composition; (b) an active region having 45 stages and emitting at a wavelength of 9 μm; (c) an energy spacing E54 of 60 meV; (d) an energy spacing EC4 of 430 meV; and (e) an optical waveguide with 3 μm thick cladding layers adjacent the active region, the cladding layers having a doping level of 2·1016 cm−3, the optical waveguide further having a 4 μm thick top InP layer with a doping level of 5·1016 cm−3 and a 2 μm thick bottom InP layer with a doping level of 5·1016 cm−3, the optical waveguide further having a 1 μm thick plasmon layer with a doping level of 8·1018 cm−3, where the optical waveguide results a free-carrier waveguide loss of 2.1 cm−1 and a mode overlap factor with the active region of 52%.