Laser confocal microscope with a Mexican hat wavelet-like point spread function

Abstract

We report a laser-scanning confocal reflectance microscope with a wavelet-like point-spread function (PSF) for rapid multi-resolution extraction and analysis of microscopic object features. The PSF is generated holographically by encoding a π-phase shifting disk unto a collimated laser beam via a phase-only spatial light modulator located at the pupil plane of the focusing objective lens. Selection and scaling of the wavelet PSF is accomplished by setting the ratio of the π-phase shifting disk radius and the pupil aperture radius. Generated transverse amplitude PSF distributions are accurate representations of scaled circularly symmetric Mexican hat wavelet.