Time-resolved reflectance and transmittance measurements of laser-induced free carriers in germanium, silicon, and zinc selenide at 10.6 microm.

We present experimental results of reflectance and transmittance measurements of infrared radiation by high-density photogenerated free carriers in polycrystalline germanium, polycrystalline silicon, and chemical vapor deposition zinc selenide windows. Linearly polarized 1064 and 532 nm wavelength light from a Nd:YAG laser with a 130 ps pulse width were used to generate free carriers in the samples. Reflectance and transmittance were measured at a 10.6 microm wavelength using a linearly polarized CO2 laser.