Optical side-band generation in THz Fabry-Perot laser cavities

Abstract

Optical nonlinearities in semiconductor laser cavities can be exploited to characterize the properties of laser radiation or perform high speed frequency conversion operations. For example, nonlinear upconversion inside the cavity of quantum cascade lasers allows the use of near infrared optical components 10 to measure high-speed terahertz or mid-infrared optical effects. This letter investigates two aspects of cavity up-conversion which control both the bandwidth and up-converted power; waveguide dispersion and cavity feedback. Specifically, we up-convert multi-mode Fabry Perot terahertz laser emission and detect each THz mode as a sideband signal on an optical carrier in the near infrared. Analysis of these results shows that a single frequency near infrared laser can up-convert terahertz modes spanning a 15 bandwidth of approximately 220 GHz; limited by the group index mismatch between the near infrared and terahertz waves. Secondly, transfer matrix techniques are used to study strong cavity feedback on all three waves, which produces etalon-like resonances in the sideband power. This can significantly enhance the efficiency of the conversion process, in agreement with experiments. It is thus possible to achieve high up-conversion efficiency in quantum cascade lasers for both characterizing broadband laser sources 20 and performing frequency conversion in the near infrared.

Ultra‐fast dynamic nonlinear mechanism of Fabry–Perot cavity with femtosecond pumping

“…The Fabry–Perot (FP) cavity is a basic and important optical device that plays an important role in the design of various types of optical devices and exhibits wide applications. To date, many researchers have devoted considerable effort to the nonlinear dynamic effects of the FP cavity and have developed many novel optical devices, such as interferometers, 1,2 resonators, 3,4 lasers, 5,6 amplifiers, 7,8 optical bistability, 9,10 and other applications 11,12 …”

“…The Fabry-Perot (FP) cavity is a basic and important optical device that plays an important role in the design of various types of optical devices and exhibits wide applications. To date, many researchers have devoted considerable effort to the nonlinear dynamic effects of the FP cavity and have developed many novel optical devices, such as interferometers, 1,2 resonators, 3,4 lasers, 5,6 amplifiers, 7,8 optical bistability, 9,10 and other applications. 11,12 In addition, the FP cavity can be combined with other materials or structures to realize a variety of optical devices through the resonance of different optical modes to enhance the field, resulting in refractive index sensing.…”