Abstract

Confocal laser microscopy (CLM) provides a means of noncontact surface profiling by virtue of its depth discrimination property.¹ A sharp discrimination signal which is, in effect, the derivative of the intensity response of the CLM, was demonstrated by dithering a sample while demodulating the response.² To obtain a similar discrimination signal, we use two point-detectors offset slightly in opposite directions from the image planes so that the difference between the two detectors’ outputs becomes the quasi derivative of the CLM response. This technique obviates the need for vibrating the sample or the optical system, thus making the implementation of the technique more convenient.

© 1991 Optical Society of America