Evaluation of the possibility of applying the method of the laser triangulation to measurement of thin film thickness

In this article the problem of measuring the thickness of thin films by laser triangulation is studied. An expression relating to the value of the film thickness and the coordinates of the rays on the photodetector is obtained. Experimental demonstration of the possibility of using this method to measure the thickness in the range [0.1, 1] mm is proposed. The results can be used in ophthalmology for the rapid diagnosis during operations in the stratum corneum. Model human cornea is a thin transparent film on the water. Camera with CCD matrix is used as photodetector.
The authors estimate of the minimum possible for film thickness, which can be measured in this experiment. The numerical value of it is in the vicinity of 0.1 mm. The smallest thickness value obtained in the experiment for a given method and parameter setting data is 0.23 mm. This method can also be used for thicknesses <0.23 mm by using a short-wave radiation and a corresponding receiver.