Paper
1 April 2005 Recent progress in nonlinear quantum cascade lasers
Oana Malis, Alexey Belyanin, Deborah L. Sivco, Jianxin Chen, A. M. Sergent, Claire Gmachl, Alfred Y. Cho
Author Affiliations +
Abstract
Nonlinear light generation in quantum-cascade lasers (QCLs) has the potential to extend the operating wavelength of these devices outside the limits imposed by the fundamental properties of the materials of choice. The giant nonlinear susceptibilities of resonant intersubband transitions have been studied intensively both theoretically and experimentally over the past twenty years. However, the practical applications have been limited by the lack of efficient laser pumping and of convenient phase matching techniques. The first obstacle was overcome by monolithically integrating the nonlinear intersubband transitions within the active region of a quantum cascade (QC) laser. Sum-frequency and second-harmonic (SH) generation were the first nonlinear processes observed in QCLs. The optimization of the second-harmonic generation in InGaAs/InAlAs QCLs will be discussed in detail. The second challenge for achieving high efficiency nonlinear power conversion is the phase-matching of the fundamental and nonlinear light. We have developed a technique for modal phase-matching that takes advantage of the flexibility in the design of the QCL waveguide. An additional degree of freedom for tuning into exact phase-matching conditions is provided by the dependence of the refractive indices on the laser ridge width. Record nonlinear power of 2 mW at 4.45 mm was achieved using an InP top-cladding waveguide and high-reflectance coating on the laser back facet. Reaching the milliwatt power range is significant as such power levels are sufficient for trace gas point sensors using mid-infrared light sources. The practical limitations of the phase-matching method will be evaluated and the experimental results will be compared with theoretical predictions.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Oana Malis, Alexey Belyanin, Deborah L. Sivco, Jianxin Chen, A. M. Sergent, Claire Gmachl, and Alfred Y. Cho "Recent progress in nonlinear quantum cascade lasers", Proc. SPIE 5738, Novel In-Plane Semiconductor Lasers IV, (1 April 2005); https://doi.org/10.1117/12.589510
Lens.org Logo
CITATIONS
Cited by 1 scholarly publication.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Quantum cascade lasers

Waveguides

Refractive index

Second-harmonic generation

Sensors

Phase matching

Indium gallium arsenide

Back to Top