Abstract

Optical scanning systems are broadly used in a variety of imaging schemes in microscopy. However, the image processing operations achievable with a scanning optical system are limited to those corresponding to a real and positive point spread function.¹ An optical heterodyne laser scanning system has been introduced to overcome the constraints.² Here, we investigate the defocusing imaging effect on the optical transfer function (OTF) of the optical heterodyne scanning system and discuss the synthesis of OTFs from defocused 2-D OTFs. Through analytical and simulation results, we show the synthesis of 3-D OTFs using two spatially separated scanning Gaussian laser beams as one example, and two superimposed Gaussian beams apodized by complementary Fresnel zone plates as another example. Low frequency de-emphasis of the obtainable 3-D OFTs is achieved.

© 1991 Optical Society of America