Dr. Jen Aitken, Department of Chemistry and Biochemistry, Duquesne University
Currently the only way to access the mid-IR spectral region using all solid-state laser (SSL) technology is with the use of down-conversion processes, such as second harmonic generation (SHG), implementing nonlinear optical (NLO) crystals. Yet, the current commercially-available IR NLO crystals have several shortcomings, including multiphoton absorption effects and low laser-induced damage thresholds (LIDTs) that limit the wavelength range and power output of the devices. Several groups are searching for new IR NLO materials implementing different strategies with hopes to access noncentrosymmetric (NCS) materials, because the lack of an inversion center is the first criterion for an SHG crystal. Our group has chosen to pursue the family of quaternary diamond-like semiconductors because their compositions are predictable based on valence electron rules and their structures are inherently noncentrosymmetric. Recently, we have identified several outstanding quaternary diamond-like semiconductor chalcogenides with strong SHG, impressive LIDTs and phase-matchability over a wide region. This seminar will discuss those results and outline future steps to elevate these materials to next-generation candidacy.