Influence of the light intensity on the operation of the self-oscillation photoacoustic setup
Independent researcher, Baborowska 5/18, 01-464 Warsaw, Poland
2 Institute of Electronic Systems, Warsaw University of Technology, Nowowiejska 15/19, 00-665 Warsaw, Poland
In the traditional approach to photoacoustic measurements, the light source modulation frequency is fixed, or a resonance tracking mechanism is applied, that adjusts the modulation frequency to the instantaneous value of the resonance frequency of the cell, especially in the case of high Q-factor cells. However, photoacoustic measurements can also be based on a novel method in which the light intensity is modulated by the photoacoustic signal induced in the cell, hence forming a photoacoustic oscillator. Frequency of such an oscillator and shape of the resulting photoacoustic signal depend mainly on the resonance properties of the cell, but also on the power of the light irradiating the investigated sample. This paper describes the influence of the intensity of light used for exciting the photoacoustic signal on the operation of such a photoacoustic generator.
© EDP Sciences, Springer-Verlag, 2008