First measurement of spectrum of two-photon absorption coefficient for CdSe based on z-scan technique using subpicosecond laser pulses

Summary form only given. Spectrum of two-photon absorption (TPA) coefficient is crucial for its applications in optical power limiting and autocorrelation. CdSe has fairly large values of TPA coefficient and a wide transparency range (0.75-25 /spl mu/m). Even though the value of the TPA coefficient for CdSe has been measured previously, the results obtained by different groups are quite different. To the best of our knowledge, for CdSe only two wavelengths, 1.06 /spl mu/m and 1.32 /spl mu/m, have been used as the pump wavelengths for studying TPA. Here, we report our first results on the measurement of the spectrum of the TPA coefficient for CdSe based on z-scan technique using subpicosecond laser pulses. We have used extremely high laser intensities while keeping the average laser powers low enough to avoid any thermal effect.