%0 Journal Article %K Measurement %K Transmission %K Beam %K Picosecond %K Spectra %K Spectrum %A M. M Cynthia Hipwell %A Chang-Lin Tien %A Xianglei Mao %A Richard E Russo %B Experimental Heat Transfer %D 1998 %G eng %N 4 %P 281-297 %R 10.1080/08916159808946566 %T The dual beam picosecond continuum technique for measurement of short time-scale transmission spectra %V 11 %2 LBNL-43857 %8 04/1998 %) Laser %X

In this work, a dual-beam measurement technique is presented to measure the short-time-scale optical properties of novel materials. It is shown that the picosecond continuum probe source obtained from nonlinear interaction with H2O/D2O is highly variable and does not permit detection of small changes in absorption /transmission spectra. The dual-beam approach is proposed to allow simultaneous measurement of a sample's properties in both the excited and steady states. As an example, the technique is applied to the picosecond transmission spectrum of light-emitting porous silicon. Photo-induced absorption is observed at a level that could not be detected without the new technique.