الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Photothermal spectroscopies are powerful techniques for measuring optical and thermal properties of soild samples, through detection of heat generated within the sample by nonradiative relaxation process. Among the better known examples of these spectroscopies are photothermal deflection spectroscopy (PDS) and photoacoustic spectroscopy (PAS). Both spectroscopy measure the heat generated in the materials due to absorption of photons either optically in the case of PDS or acoustically in the case of PAS. the PDS is based on the sensitive detection of thermal gradient adjacent to the heated sample surface, while the basic idea of PAS is the production of acoustic signal from a sample in a closed cell containing gas (air) and a sensitive microphone when it is illuminated with a chopped light.
In this work : first we have employed the PDS and PAS techniques to determine the thermal properties of opaque soilds (semiconductors InAs). second, as an application of transverse PDS we use depth profile analysis to detect defects of diiferent sizes and different shapes at different depths from the surface of the aluminum samples. Also we detect defects of different thermal conductivities. Finally we use the transverse PDS to study the absorption of H2 into thin film pd deposited on silicon substrate. Complete theoretical treatments of the two techniques PDS and PAS are presented that include: *The solution of heat diffusion equations in the sample and surrounding media using the incident beam as the source term of the heat diffusion equation.
* The temperature distribution in each media.
* The PD signal as well as the PAsignal as a function of heat generation due to light absorption.
* The PD signal ang PA signal for rear surface illumination which is used to measure thermal parameter of optically opaque sample (InAs semiconductor).