The phenomenon of polarization has now become important in the field of optical imagery. It is well-known that the imaging properties of optical systems are determined by the diffraction properties of their apertures. This calls for a systematic study of diffraction properties of different apertures in presence of zonal masking devices. In the present paper, we study the diffraction properties of a circular aperture where the zonal polarization masks are mutually orthogonal. The variation of the PSF and OTF of such a system with the orientation of the analyzer placed at the output side have been studied. © 2012 Elsevier GmbH. All rights reserved.

KALLOL BHATTACHARYA

Applied Optics and Photonics

M TAHIR

A GHOSH

A K CHAKRABORTY

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

&nbsp;

The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

&nbsp;

It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Optik

One approach to aberration compensation of an imaging system is to introduce a suitable phase mask at the aperture plane of an imaging system. We utilize this principle for the compensation of astigmatism. A suitable polarization mask used on the aperture plane together with a polarizer-retarder combination at the input of the imaging system provides the compensating polarization-induced phase steps at different quadrants of the apertures masked by different polarizers. The aberrant phase can be considerably compensated by the proper choice of a polarization mask and suitable selection of the polarization parameters involved. The results presented here bear out our theoretical expectation. © 2004 Optical Society of America.

Fulltext

Applied Optics

Polarization-based compensation of astigmatism

It is well known that circular symmetric phase and amplitude coatings on the lens aperture modify the imaging qualities of a lens. The present paper shows that the effects of such phase and amplitude coatings on the imaging properties of a lens can be achieved by using suitably oriented polarization masks on the lens aperture. The fact that the response of such a system can be continuously varied by changing the orientation of the polarizing devices included in the system lends it a versatility unobtainable by the use of conventional phase and amplitude coatings on the lens aperture. © 1994 Optical Society of America.

Journal of the Optical Society of America A: Optics and Image Science, and Vision

Simulation of effects of phase and amplitude coatings on the lens aperture with polarization masks

The optical transfer function (OTF) of an imaging system using polarization devices depends in general on the state of polarization of the input beam. In fact, the `amplitude point spread function' (APSF) of such a system is different for different linearly polarized components of the input beam. This implies that the APSF of a system using polarizing devices behaves as a vector quantity. The nature of the final image is determined by the relative contribution of the two components of the vector APSF. The specific imaging system considered in the present study consists of a circularly symmetric polarization mask with linear polarizers having different orientations for the central circular and annular regions of an ideal lens aperture. If the light originating from an object point is in general elliptically polarized, the OTF of such a system with an analyser at the output is seen to have three additive components, which are, in fact, the Fourier coefficients of the OTF which varies periodically with the orientation of the analyser. It is also observed that the images produced by each additive component of the OTF can be separated—a fact that seems rewarding in view of potential applications. © 1993 Taylor and Francis Ltd.

Journal of Modern Optics

Vector wave imagery with a lens masked by polarizers

The imaging characteristics of a perfect lens partially masked by a linear polarizer can be varied continuously either by rotating an analyzer placed at the output side or by changing the state of polarization of the input beam. In this paper we study the frequency-response characteristics and the point-spread function of such a system. It is also shown that the proposed system can be adapted either for apodization or for superresolution simply by rotating the analyzer. The fact that the unpredictable phase introduced by the mask has no harmful effect on the performance of the system makes it convenient for several applications. Expressions are obtained for the optical transfer function and the point-spread function of such a system. Some specific cases are illustrated graphically, and some probable applications are discussed. © 1988 Optical Society of America.

Frequency-response characteristics of a perfect lens masked by polarizing devices

The optical frequency response of a perfect lens partially masked by a retarder has been studied . The optical transfer function (OTF) of such a system depends upon the relative orientation of the analyser, placed at the output, relative to the slow and fast axes of the mask, and also on the relative aportioning of the lens aperture by the mask . The OTF of the system also depends upon the retardation introduced by the mask . In the present paper, we have computed the OTF of the masked lens for different values of the relevent parameters with and without the analyser at the output. © 1987 Journal Of Modern Optics. All rights reserved.

Journal	Data powered by TypesetOptik
Publisher	Data powered by TypesetELSEVIER GMBH, URBAN & FISCHER VERLAG
ISSN	0030-4026
Open Access	No