Generation of Broad Spectral Components from Mid-Infrared Ultrashort Pulse Laser Propagation through Single- and Poly-Crystalline Optical Materials

We investigated the nonlinear optical properties of single- and poly-crystalline optical materials using ultrashort mid-infrared laser pulses between 3 and 4 μm. We compared visible to mid-infrared spectra between the materials. Measured energy conversion into all-order harmonics in polycrystalline materials exceeded 30%.