Bessel beam based optical profilometry

We present our results of the development of some schemes for nondestructive optical profilometry of cylindrically shaped surfaces by using spatially matched conical light beams. A theoretical model is elaborated which describes profilometers with Bessel beams. A special feature of the profilometers proposed is the possibility to control their sensitivity and resolution. To this end, a scheme of tuning the cone angle of the Bessel beam over a wide range is incorporated. The operation regime of the profilometers is characterized by a nonzero spatial frequency of output signal. It allow us to apply a new algorithm for the interpretation of the output signal. This algorithm consists in the calculation of the azimuth spectrum which characterizes the deviation of tested profiles from the circular ones.