Confocal scanning microscope(CSM) is very useful tool for measurement in biological field, material science and semiconductor industry because of its providing images with superior resolution and its unique property of optical sectioning. These properties are cause by confocal aperture which prevents out of focus information.
In this paper we designed beam scanning optical system for reflection confocal microscope using acousto-optical deflector(AOD). AOD has low diffraction efficiency below 70%, so they cannot be descanned by the AOD. So we collect reflected light from specimen with slit rather than pinhole directly.
In beam scanning system the aberration of optical components effect on the performance of CSM, so careful selection of optical components is very important. We propose a method to design a scanning system using the finite ray tracing and diffraction theory and define a cost function which contains the effect of aberration. The design variables are lenses and their locations and determined to minimize the cost function. The lenses are all doublets.
We construct the designed system and evaluate its performance. The FHWM which means axial performance of CSM is not changed with deflection angle. We conclude that the beam scanning system is properly designed. And we got some images of specimen with designed reflection confocal scanning microscope.