Study On Modulated Dual Beam Thermal Lens Technique

Laser thermal lens technique is one of the photo thermal methods, which rely on the measurement of heat generated from non-radiative relaxation processes following absorption of optical radiation. Because of its extremely high sensitivity, low detection limit and the capability of measuring micro samples, in recent years various applications of thermal lens technique have been developed over a wide range of science and technology, including chemistry, physics, electronics, material engineering, environmental and life science and etc. And lots of methodological studies including theory and instrumentation have been done in recent years. While there are few researches dedicated to modulated thermal lens, which can acquire the physical character of the sample by the frequency response of the signal and also has the advantage of using lock-in amplifier to improve the signal-noise ratio. This research mainly focuses on the development and optimization of optical-scheme configuration of modulated thermal lens technique .The main points of this dissertation are following:1. A review of Laser Thermal lens technique in terms of the development in instrumentation and applications to the analytical chemistry is given.