Suitability of holographic beam scanning in high resolution applications

Kalita, Ranjan; Buddha, S S Goutam; Boruah, Bosanta R.

doi:10.1117/12.2287804

Cited by 3 publications

(1 citation statement)

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“…4,5 Therefore, these modes find applications in testing optical systems, adaptive optics, wavefront sensing and free space optical (FSO) communication systems. [6][7][8][9] Zernike modes have been used in ophthalmology for corneal study, 10 wavefront corrections for surface and thickness profile mesurement of thin film 8,11,12 and wavefront estimation, 13,14 aberration correction in microscopy [15][16][17] and micromanipulation of optical trapping. 18,19 In all these applications, the orthogonal property is the primary reason for their use.…”

Section: Introductionmentioning

confidence: 99%

Orthogonality of Zernike modes in phase profiles estimated using Zonal wavefront sensor and transport of intensity phase retrieval method

Chauhan

Sherpa

Kumar³

et al. 2023

Quantitative Phase Imaging IX

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Zernike polynomials are orthogonal polynomials that form a complete basis set and can be easily used to describe aberrations present in an optical system. Zernike modes find applications in various fields like adaptive optics (AO), optical imaging, ophthalmology, free space optical (FSO) communication, etc. Since the modes are orthogonal, they can express any arbitrary wavefront as their linear combinations. The orthogonality of the modes enables the calculation of the expansion coefficients and suggests the independent behaviour of the Zernike mode. In this work, we numerically estimate the wavefront, defined as Zernike modes, using various state of the art phase retrieval methods. We use the Zonal wavefront sensor (ZWFS) and Transport of Intensity Equation (TIE) for phase reconstruction and then calculate the orthogonality between reconstructed Zernike modes. It is found that the reconstructed Zernike modes are not perfectly orthogonal, which is mainly due to the discrete representation of the Zernike modes. We further investigate how the change in the number of zones in a ZWFS affects orthogonality. We also simulate TIE to retrieve the phase and compare the orthogonality results with ZWFS. This study will be helpful in applications where a wavefront described using Zernike mode needs to be reconstructed, and improvement in the orthogonality is required, which is achieved by increasing the number of zones in the ZWFS and representing Zernike modes in a more continuous form.

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Section: Introductionmentioning

confidence: 99%

Orthogonality of Zernike modes in phase profiles estimated using Zonal wavefront sensor and transport of intensity phase retrieval method

Chauhan

Sherpa

Kumar³

et al. 2023

Quantitative Phase Imaging IX

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Holographic scanning confocal microscopy for both reflected light and fluorescence light imaging

Kalita

Saikia²,

Bhuyan³

et al. 2019

Review of Scientific Instruments

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In this paper, we propose a holographic scanning based confocal microscope that works in both the reflection and fluorescence modes. Here, the illumination beam is scanned using a reconfigurable binary hologram instead of a usual galvanometer mirror scanner. The reconfigurable hologram is implemented using a liquid crystal spatial light modulator. Two different lasers are used for fluorescence and reflection mode imaging with the phase profile of the illumination beam, derived from each laser, described by the holograms. We demonstrate the working of our microscope in both the modes by imaging a section of tooth specimen stained with a fluorescent dye.

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