Design and development of volume phase holographic grating based digital holographic interferometer for label-free quantitative cell imaging

Abstract

In this paper, a volume phase holographic optical element based digital holographic interferometer is designed and used for quantitative phase imaging of biological cells [white blood cells, red blood cells, platelets, and Staphylococcus aureus (S. aureus) bacteria cells]. The experimental results reveal that sharp images of the S. aureus bacteria cells of the order of ∼ 1 µ m can be clearly seen. The volume phase holographic grating will remove the stray light from the system reaching toward the grating and will minimize the coherent noise (speckle noise). This will improve the sharpness in the image reconstructed from the recorded digital hologram.

3D Measurements and Characterizations of Refractive Index Distributions of Volume Holographic Gratings Using Low‐Coherence Holotomography

“…[7] A critical parameter of a grating is its diffraction efficiency, [8] and a volume holographic gratings' diffraction efficiency can theoretically attain up to 100%, which greatly surpasses the maximum 33.8% and 40.5% efficiencies achievable by thin sinusoidal and binary phase gratings. [9] These salient features position VHGs as vital tools in imaging, [10] biophotonics, [11] and display technologies. [12] Despite remarkable progress in the materials and techniques for recording gratings since the advent of VHGs, [13] methodologies for investigating and characterizing VHG and HOE remain largely untapped.…”

“…[ 7 ] A critical parameter of a grating is its diffraction efficiency, [ 8 ] and a volume holographic gratings' diffraction efficiency can theoretically attain up to 100%, which greatly surpasses the maximum 33.8% and 40.5% efficiencies achievable by thin sinusoidal and binary phase gratings. [ 9 ] These salient features position VHGs as vital tools in imaging, [ 10 ] biophotonics, [ 11 ] and display technologies. [ 12 ]…”

Volume phase holographic grating based digital holographic interferometer for temperature measurement of human hand skin

“…interferometry (DHI) is one of the optical interferometric techniques which has been extensively used in numerous applications [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44].…”

“…In the presented system, VPHG has been used as a beam splitter and spatial filter. Due to high angular and wavelength selectivity, VPHG will minimize the effect of the stray light and high frequency speckle noise in the system [31]. The advantage of the proposed system is that it is non-contact, non-invasive, fast, compact, requires lesser number of optical components, simple to align, robust, and easy to use [31].…”