Multi-spectral quantitative phase imaging based on filtration of light via ultrasonic wave

Abstract

A new digital holographic microscopy scheme for multi-spectral quantitative phase imaging is proposed and implemented. It is based on acousto-optic filtration of wide-band low-coherence light at the entrance of a Mach-Zehnder interferometer, recording and digital processing of interferograms. The key requirements for the acousto-optic filter are discussed. The effectiveness of the technique is demonstrated by calculating the phase maps of human red blood cells at multiple wavelengths in the range 770–810 nm. The scheme can be used for the measurement of dispersion of thin films and biological samples.

Lens-in-lens common-path interferometer for quantitative phase imaging

“…Interference fringe patterns captured using the LiL-CPI do not differ radically from the patterns obtained in other offaxis DH schemes [3,4,18]. The image processing technique is classical: selection of diffracted beam (1st order), its centering, amplitude and phase extraction, phase unwrapping [18,20]. These procedures are standard mathematical operations and may be implemented in real-time mode.…”

“…Component L2 collimates both beams and brings them together in the sensor plane where the interference pattern is captured. The optical phase delays induced by the object are then calculated and analyzed in each pixel using the digital processing algorithms [18].…”

Lensless Three-Dimensional Quantitative Phase Imaging Using Phase Retrieval Algorithm

“…Quantitative phase imaging (QPI) techniques enable the measurement of thickness and refractive index variations in optically transparent objects, and have been widely used to study unstained biological samples, which modulate the phase but not the amplitude [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ]. A wide variety of techniques, such as Schlieren method [ 4 ], Zernike phase contrast method [ 5 ], tomography [ 6 ], interference microscopy [ 7 , 8 , 9 ] and digital holography [ 10 ] can be applied for QPI applications.…”

“…In this technique, two orthogonally polarized, mutually coherent and spatially separated light waves are interfered with, and the relative phase differences are imaged. In subsequent studies, interferometry and digital holography techniques evolved into reliable phase imaging methods [ 12 , 13 , 14 ]. In most of the interference based phase imaging applications, a coherent light source is split into two: one of the beams passes through the sample, while the other beam is used as a reference.…”

Акустооптический Гиперспектральный Модуль Для Гистологического Исследования Микрообъектов

“…Исследования [11,12] показывают, что раковые клетки обладают более высоким показателем преломления по сравнению с нормальными клетками. Однако в известных на сегодняшний момент установках измерение пока-зателя преломления ведется либо в монохроматическом, либо в белом свете, в то время как дополнительное исследование присущей веществам дисперсии за счет регистрации цифровых голограмм в узких спектральных каналах в широком диапазоне спектра позволило бы повысить информативность и точность диагностики, а также выявить новые закономерности за счет детального анализа молекулярного состава вещества [13,14].…”