Image restoration for SAM using computed optical transfer functions

A theory for surface structure imaging is presented, which allows the computation of optical transfer functions (OTF) of the scanning acoustic microscope (SAM). The model describes the monitor image in terms of the reflectivity of the specimen, thus including the influence of the confocal lens system and subsequent signal processing. Amplitude and phase contrast imaging in SAM are defined, and the corresponding OTF computed for different focus positions are shown to be in good agreement with measurements. Based on the theoretical OTF, an image restoration scheme for phase contrast imaging is developed. Combining images of a focal series, the imaging properties of SAM for phase contrast can be improved