STP799: Two-and Three-Photon Absorption in Semiconductors with Subsequent Absorption by Photogenerated Carriers

    Van Stryland, EW
    Center for Applied Quantum Electronics North Texas State University, Denton, Texas

    Woodall, MA
    Center for Applied Quantum Electronics North Texas State University, Denton, Texas

    Williams, WE
    Center for Applied Quantum Electronics North Texas State University, Denton, Texas

    Soileau, MJ
    Center for Applied Quantum Electronics North Texas State University, Denton, Texas

    Pages: 12    Published: Jan 1983


    Abstract

    A careful examination of two-photon absorption in CdTe and three-photon absorption in CdS and ZnSe was made by studying the transmission of picosecond pulses at 1.06 μm and the photoacoustic signal generated in the sample by the absorption of light. We found that in order to separate the direct nonlinear absorption from the subsequent absorption by the photogenerated carriers, careful analysis of the data over a wide range of irradiance levels was necessary. The nonlinear absorption coefficients for these three materials were determined, as well as an overall excess carrier absorption cross section. In addition, for CdTe we used two different temporal pulsewidths to verify our analysis. The photoacoustic data had a 1 to 1 correspondence with the transmission data indicating that this more sensitive technique should be useful for measuring nonlinear absorption spectra in solids with a variety of less powerful lasers. In addition for samples such as BK7 glass, which showed no nonlinear transmission even when surface damage occurred, the photoacoustic signal showed abrupt large increases when damage occured. No nonlinear absorption was observed in two types of CVD ZnS prior to damage.

    Keywords:

    nonlinear absorption, photoacoustic, two-photon, three-photon, CdTe, CdS, ZnSe


    Paper ID: STP37286S

    Committee/Subcommittee: F01.02

    DOI: 10.1520/STP37286S


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