A SINGLE AND SIMPLE MATHEMATICAL EXPRESSION OF THE SIGNAL FOR CW-LASER THERMAL LENS SPECTROMETRY

Since the discovery of the thermal lens effect, several theoretical mo dels have been put forward for cw-laser thermal lens spectrometry and different expressions of the thermal lens signal have been derived for various optical configurations including single-beam or dual-beam sit uations. This review focuses primarily on the successive mathematical expressions reported so far for both steady-state and time-reserved me asurements, with the aim of comparing them in order to propose a singl e and convenient relation that accurately accounts for the sensitivity and the temporal behaviour of the thermal lens effect.