PSF with Partial and Variable Apodization along with CPF

The point spread function (PSF) of aberrated optical system apodized with Hanning and Lanczos amplitude filters has been determined. The influence of phase mask also considered for various zones of the aperture. For this study rotationally symmetric coherent optical system has been considered. INTRODUCTION Coherent illumination of the object is essential in order to get narrow bandwidth spectra and very high degree of collimation as is required in speed photography and illumination of photosensitive materials. Coherent imagery is highly desirable for microscopy and spatial filtering. With the advent of laser, it became easy and convenient to obtain perfect coherence over the entire object plane and coherent optical systems found wide range of applications in the fields of communication, information processing, image processing, medical imaging, life sciences, defense, research, education, industrial, holography and Ophthalmology etc. The point spread function, the response of an imaging system to a point object, allows a comparison of the performance of different imaging systems. Asakura and Mishina (1970), studied both amplitude and irradiance of PSF in the diffraction by circular apertures with ring shape producing π phase change. Rao, Mondal, (1976) have studied the amplitude and irradiance PSF for Straubel class of apodization filters. L.N. Hazra(1977), in his investigation of a new class of optimum amplitude filters for maximizing the encircled energy factor, studied the irradiance of PSF. He employed a set of radial Walsh functions as the system of base functions. L.N.Hazra etl. (2010) investigated the use of phase annuli as pupil filters in tailoring of both transverse and axial resolution. They also carried out a systematic study on the use of phase filters on annular pupils with the help of annular Walsh filters (2013) . Viswanatham(1981) employed triangular and associated filters to apodize the optical system and studied the PSF at the Gaussian focal plane and at various defocused planes. Yzuel, M. J. and Campos,J. studied the effects of several filters on the axial and extra-axial point-spread function (PSF) and modulation-transfer function (MTF) of an optical system for different filter positions. M. Martínez etl. (2002) presented a procedure for shaping the axial component of the point spread function of non paraxial focusing systems by use of phase-only pupil filters . The procedure is based on the Toraldo technique for tailoring focused fields. The resulting pupil filters consist of a number of concentric annular zones with constant real transmittance. In the previous paper we (2014) have studied the edge response of an aberrated optical systems using multi-shaded aperture apodization technique. In this work the influence of complex pupil function (CPF) and amplitude apodization on the intensity point spread function of coherent optical system is investigated. We have developed a general expression for the intensity point spread function in the case of circular aperture when the aperture is divided into two zones and is apodized with two different amplitude transmission functions along with phase. International Journal of Engineering Technology, Management and Applied Sciences www.ijetmas.com June 2017, Volume 5, Issue 6, ISSN 2349-4476 197 M. Venkanna and D. Karuna Sagar THEORY The diffracted light amplitude associated with a rotationally symmetric pupil is given by 11, 12    rdr Zr J r f Z A 0 1