Features of image colouring in a projection microscopebased on a copper vapour laser with an unstable resonatorand a Glan prism

The effect of properties of metal surfaces on the colour of their images obtained with a 510.6/578.2-nm copper vapour laser projection microscope is studied. The metal surfaces were exposed to laser radiation polarised by 99 % in the horizontal plane. Radiation used for surface imaging is predominantly polarised in the vertical plane and is coupled out of the resonator in the direction perpendicular to its optical axis. It is found that the ratio of laser radiation powers at wavelengths 510.6 and 578.2 nm determining the image colour is dependent on the total reflection coefficients, the curvature, and statistical characteristics of the surface roughness.