Abstract

The optical frequency comb synthesizer (OFCS) is nowadays a fundamental tool for near infrared spectroscopy and metrology. Since the fundamental ro-vibrational transitions of simple molecules fall in the mid-infrared (MIR), it is of particular interest for spectroscopy applications to have OFCSs operating in this spectral region. Quantum cascade lasers (QCLs) have proved to be sources capable to generate frequency combs (QCL-combs) [1, 2]: the phase locking among the modes is guaranteed by four-wave mixing.

© 2015 IEEE