Experimental parameters choice of photo-thermal interferometric detection system

In order to study influence of experimental parameters on photo-thermal interferometric detection,according to interference principle of equal thickness,a theory model is set up by means of Seidel aberration of tilt.After various probe beams are investigated,a universal light model is proposed by means of random function,and uniformity of the light source is defined.Based on this model,it is simulated that interferometric experimental phenomena change with various probe beam,and the influence of probe's uniformity is analyzed on interferometric measurement,which show there are no difference among various probe beam.On the other hand,the influence of detector's aperture on interferometric measurement is analyzed.Results show it is the best when radius of detector's aperture is 0.315cm.Under this condition,photo-thermal signal descends monotonously during fine scale photo-thermal displacement of 0~0.6λ,and the contrast of interferometric stripe is better.Under weak absorption,a simple experiential equation between photo-thermal signal and photo-thermal displacement can be concluded by curve fitting.