Harmonics Generation in Large-Mode-Area Cr:ZnS Waveguide Amplifier

Abstract

The mid-infrared (mid-IR) wavelength range between 2 and 5 µm, which is often called a “molecular fingerprint” region, is characterized by the presence of strong fundamental and overtone rovibrational absorption bands of atmospheric constituents, vapors, and gases, such as carbon monoxide and dioxide, methane, ammonia, NO<inf>x</inf>, etc. This makes ultra-broadband Cr²⁺- II-VI compound-based lasers particularly attractive for various environmental and climate change-related sensing tasks [1-3]. Due to the lattice-matched to Si and because the Cr²⁺:ZnS operation wavelength range of 2-3.1 µm lies well in the transparency window of Si, Cr²⁺-doped ZnS laser may provide a path for direct integration with Si photonics allows for high-power broadest tunable and few-cycle ultrafast laser operation, including frequency combs even in the directly diode-pumped setups.