ON THE SIMULTANEOUS EFFECT OF BEAM DEFLECTION AND THERMAL LENSING PHENOMENA IN PHOTOTHERMAL SPECTROMETRY

A general model that accounts for a combined effect of thermal lensing and photothermal beam deflection was derived. The model enables the e stimation of contributions to the measured photothermal signal from ea ch of the two phenomena. Experimental parameters such as modulation fr equency, the pump beam diameter, and the position of detector can be o ptimized using this model in order to minimize the unwanted effects of misalignment or laser pointing instability, and to improve the accura cy of thermal lens and photothermal beam deflection spectrometry.