An interferometric method for quantitative evaluation of the magnitude and direction of birefringence of an arbitrarily oriented birefringent sample is developed and presented. The analysis shows that full-field analysis of a spatially varying birefringence is possible by suitably combining several interferogram frames obtained by varying the polarization parameters involved. The preliminary experimental result for a uniformly birefringent sample with a known direction of birefringence is presented. © 2015 Society of Photo-Optical Instrumentation Engineers (SPIE).

KALLOL BHATTACHARYA

Applied Optics and Photonics

S SIRCAR

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.

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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.

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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

Measurement of birefringence using polarization phase-shifting Mach–Zehnder interferometer

Optical Engineering

Full-field evaluation of spatially varying birefringence is realized by allowing two mutually orthogonally polarized collinearly propagating laser beams to be incident on a birefringent sample. This is achieved by use of a modified Sagnac interferometer. A half-wave plate is placed in the exit path of the interferometer to adjust the polarizations of the incident beams as required. Amplitude components of the light emerging from the birefringent object are then selected and/or combined by a polarizer, and intensities for required orientation of the half-wave plate and the analyzer are digitally recorded. It is shown that a maximum of four frames of intensity data is sufficient for complete evaluation of birefringence. The proposed technique is aimed towards birefringence measurements in microscopic biological specimens where the magnitude of retardation lies in the range of 0 − π radians. Simulated and experimental results are presented. © 2018 Optical Society of America.

Applied Optics

Quantitative birefringence microscopy with collinearly propagating orthogonally polarized beams

Measurement of birefringence using polarization phase-shifting Mach-Zehnder interferometer

A full-field technique for simultaneous measurement of the magnitude of birefringence and its orientation is presented. This is achieved using a monolithic birefringence sensitive interferometer where the interference fringes carry the information of both the birefringence phase and the orientation of the fast axis of an optically transmissive anisotropic material placed at the output of the interferometer. The interferometer consists of a suitably polarization-masked cube beam splitter, orientated as in the Gates interferometer, which serves to generate a pair of orthogonally polarized and collinearly propagating light beams. Experimental results are obtained through an algorithm incorporating eight polarization phase-shifted interferograms. © 2011 Optical Society of America.

Polarization phase-shifting interferometric technique for complete evaluation of birefringence

An interferometric technique for photoelastic testing of small and transparent samples is proposed. By the introduction of two properly oriented polarisers in the two arms of a Twyman-Green interferometer, it has been shown that the modified interferometer is rendered sensitive to birefringent samples placed in the path of a plane polarised parallel beam of light entering the interferometer. Since the sample is placed in the common arm, unequal phases either inherent in the sample or due to deformation under stress will not be reflected in the output. During the testing procedure, the two arms of the interferometer can be left totally undisturbed. Information on the stress distribution over the sample area can be obtained from the recorded interferometric pattern - since the recorded fringe shifts are proportional to the developed stresses. The principle of the technique is discussed and experimental results are provided. © 1994.

Journal	Data powered by TypesetOptical Engineering
Publisher	Data powered by TypesetSPIE
ISSN	0091-3286
Open Access	No