Download or read book Mid Infrared Lasers and Their Interactions with Solids, Liquids and Plasmas written by Rotem Kupfer and published by . This book was released on 2019 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mid-infrared lasers have attracted significant attention over recent years because of the favorable scaling of many physical processes with increasing wavelength. We will present the development of mid-IR oscillators and the fabrication of gain media at UT Austin. We will then focus on two experiments using a mid-IR high average power, nanosecond laser: 1) A study of harmonic generation in polycrystalline semiconductors where we observed unusual scaling of the harmonics with the pump pulse energy. We developed a numerical model of the cascade random-quasi-phase-matched three-wave-mixing processes to explain the experimental observations. 2) A study of the plasma characteristics in laser induced breakdown spectroscopy with a nanosecond mid-IR excitation source. Using spectral measurements and a framing camera we observed a spatial separation of the plasma plume, increased emission signal with low white light generation, and a drop in the apparent plasma density with increasing pump energy. Our results can be explained by continuous heating of the plasma by the pump pulse due to the more efficient inverse bremsstrahlung absorption at longer wavelengths