arXiv subjects

Joseph Rosen

Publications and source records attributed to Joseph Rosen.

11 recordsLinked to original sources

arXiv2026

Recent advances in spatial light modulator-based three-dimensional optical imaging (Invited)

Phase-only spatial light modulators (SLMs) are used in optical systems for several purposes. In this article, the main landmarks of SLM-based imaging systems are surveyed. In addition to conventional two-dimensional imaging, these systems are useful for multidimensional imaging, axial sectioning, field-of-view expansion, improved image resolution, imaging through scatterers, and depth-of-field control. The SLMs in this review are positioned in the system aperture and modulate the input light in various ways to achieve different imaging goals. This review begins with the nearly 20-year-old Fresnel incoherent correlation holography system, continues with coded-aperture holography, and progresses to the most recent versions of interferenceless coded-aperture holography systems.

physics.optics↗

arXiv2026

Single-shot incoherent imaging with extended and engineered field of view using coded phase apertures

A large field of view of an optical system is needed for many applications, and optical systems with high magnification often suffer from a limited field of view due to the limited size of the camera sensor. This study proposes a novel technique for engineering the field of view of an optical system without compromising the magnification. In the proposed method, an object response pattern is recorded on a camera by introducing a coded phase mask (CPM) in the imaging system. The coded phase mask is a multiplexing of N distinct scattering phases, where N-1 represents the number of isolated object areas to be brought within the field of view. Each scattering phase yields a point spread function of a unique sparse dot pattern on the camera. With the introduction of a coded phase mask, the objects' images are brought within the region of the camera sensor, which, without the CPM, would have remained outside the inherent field of view of the system. To reconstruct the original object plane with N objects at their respective locations, the zero-padded object response pattern is deconvolved with the system's zero-padded and shifted point spread function. A simulation study followed by experimental results for N = 2 and N = 3 is presented in this article.

physics.optics↗

arXiv2025

Axial resolution post-processing engineering in Fresnel incoherent correlation holography

Fresnel incoherent correlation holography (FINCH) is a self-interference-based incoherent digital holography method. In FINCH, light from an object point is split into two beams, modulated differently using two lenses with different focal distances, and creates a self-interference hologram. At least three phase-shifted holograms are recorded and synthesized into a complex hologram, which reconstructs the object image without twin image and bias noises. Compared with conventional imaging, FINCH exhibits a longer depth of focus (DOF) and higher lateral resolution. In this study, we propose and demonstrate a new method termed post-engineering of axial resolution in FINCH (PEAR-FINCH), which enables post-recording DOF engineering for the first time. In PEAR-FINCH, a library of FINCH holograms catalogued with unique axial characteristics, DOF, and focus location is recorded by changing the focal distance of one of the diffractive lenses. Selected holograms from this library are combined to engineer new axial characteristics not achievable in FINCH. A two-step reconstruction, involving numerical back-propagation and deconvolution with a point spread hologram, is implemented. Experiments with multiplane objects having large axial separations confirm that PEAR-FINCH achieves a substantially extended DOF compared with direct imaging and FINCH. PEAR-FINCH will be promising for applications in biomedical imaging, holography, and fluorescence microscopy.

physics.optics↗

arXiv2021

Shack Hartmann wavefront sensor with array of phase coded masks

Shack-Hartmann wavefront sensors (SHWS) are generally used to measure the wavefront curvature of light beams. Measurement accuracy and the sensitivity of these sensors are important factors for better wavefront sensing. In this study, we demonstrate a new type of SHWS with better measurement accuracy than the regular SHWS. The lenslet array in the regular SHWS is replaced with an array of coded phase masks and the principle of coded aperture correlation holography (COACH) is used for wavefront reconstruction. Sharper correlation peaks achieved by COACH improve the accuracy of the estimated local slopes of the measured wavefront and consequently improve the reconstruction accuracy of the overall wavefront. Experimental results confirm that the proposed method provides a lower mean square wavefront error by one order of magnitude in comparison to the regular SHWS.

physics.optics↗

arXiv2020

Quantitative phase-contrast imaging: a bridge between qualitative phase-contrast and phase retrieval algorithms

In the last five decades, iterative phase retrieval methods draw large amount of interest across the research community as a non-interferometric approach to recover quantitative phase distributions from one (or more) intensity measurement. However, in cases where a unique solution does exist, these methods often require oversampling and high computational resources, which limits the use of this approach in important applications. On the other hand, phase contrast methods are based on a single camera exposure but provides only a qualitative description of the phase, thus are not useful for applications in which the quantitative phase description is needed. In this study we adopt a combined approach of the two above-mentioned methods to overcome their respective drawbacks. We show that a modified phase retrieval algorithm easily converges to the correct solution by initializing the algorithm with a phase-induced intensity measurement, namely with a phase contrast image of the examined object. Accurate quantitative phase measurements for both binary and continuously varying phase objects are demonstrated to support the suggested system as a single-shot quantitative phase contrast microscope.

physics.optics↗

arXiv2020

Coded aperture correlation holographic microscope for single-shot quantitative phase imaging with extended field of view

Recently, a method of recording holograms of coherently illuminated three-dimensional scene without two-wave interference was demonstrated. The method is an extension of the coded aperture correlation holography from incoherent to coherent illumination. Although this method is practical for some tasks, it is not capable of imaging phase objects, a capability that is an important benefit of coherent holography. The present work addresses this limitation by using the same type of coded phase masks in a modified Mach-Zehnder interferometer. We show that by several comparative parameters, the coded aperture-based phase imaging is superior to the equivalent open aperture-based method. As an additional merit of the coded aperture approach, a framework for increasing the system's field of view is formulated and demonstrated for both amplitude and phase objects. The combination of high sensitivity quantitative phase microscope with increased field of view in a single camera shot holographic apparatus, has immense potential to serve as the preferred tool for examination of biological tissues and micro-organisms.

physics.optics↗

arXiv2019

Improving Dynamic Range of Speckle Correlation based Optical Lever by spatial multiplexing

Speckle correlation based optical levers SC OptLev possess attractive characteristics suitable for sensing small changes in the angular orientations of surfaces. In this study, we propose and demonstrate a spatial multiplexing technique for improving the dynamic range of SC OptLev. When the surface is in its initial position, a synthetic speckle intensity pattern, larger than the area of the image sensor is created by transversely shifting the image sensor and recording different sections of a larger speckle pattern. Then, the acquired images are stitched together by a computer program into one relatively large synthetic speckle pattern. Following the calibration stage, the synthetic speckle intensity pattern is used to sense changes in the surfaces angular orientation. The surface is monitored in realtime by recording part of the speckle pattern which lies within the sensor area. Next, the recorded speckle pattern is a cross correlated with the synthetic speckle pattern in the computer. The resulting shift of the correlation peak indicates the angular orientations of the reflective surface under test. This spatial multiplexing technique enables sensing changes in the angular orientation of the surface beyond the limit imposed by the physical size of the image sensor.

physics.ins-det↗

arXiv2019

SLM aided noninvasive imaging through thin scattering layers

We propose and demonstrate a new imaging technique to noninvasively see through scattering layers with the aid of a spatial light modulator (SLM). A relay system projects the incoherent light pattern emitting from the scattering layer onto the SLM. Two coded phase masks are displayed, one after another, on the SLM to modulate the projected scattered field. Two corresponding intensity patterns are recorded by a digital camera, and subtracted one from the other in the computer to obtain a bipolar matrix. A modified phase retrieval algorithm is used to retrieve the object information from this bipolar matrix.

physics.optics↗

arXiv2019

Implementation of a speckle correlation based optical lever (SC-OptLev) with extended dynamic range

A speckle correlation based optical lever (SC-OptLev) is constructed for the measurement of small changes in the angle of orientation of a surface. The dynamic range of SC-OptLev is found to be twice that of a conventional OptLev for the same experimental configurations. Different filtering mechanisms are implemented and the correlation results are compared. Two types of computer automated SC-OptLevs, open source based computing system with a low-cost image sensor and a commercial computing system, are presented with assistive computational modules.

physics.ins-det↗

arXiv2019

Binary square axicon with chiral focusing properties for optical trapping

We introduce a novel phase-only diffractive optical element called chiral binary square axicon (CBSA). The CBSA is designed by linearly rotating the square half-period zones of the binary square axicon with respect to one another. A quadratic phase mask (QPM) is combined with the CBSA using modulo-2π phase addition technique to bring the far-field intensity pattern of CBSA at the focal plane of the QPM and to introduce quasi-achromatic effects. The periodically rotated zones of CBSA produces a whirlpool phase profile and twisted intensity patterns at the focal plane of QPM. The degree of twisting seen in the intensity patterns is dependent upon the angular step size of rotation of the zones. The intensity pattern was found to rotate around the optical axis along the direction of propagation. The phase patterns of CBSA with different angles of zone rotation are displayed on a phase-only spatial light modulator and the experimental results were found to match with the simulation results. To evaluate the optical trapping capabilities of CBSA, an optical trapping experiment was carried out and the optical fields generated by CBSA were used for trapping and rotating yeast cells.

physics.optics↗

arXiv2017

Incoherent digital holograms acquired by interferenceless coded aperture correlation holography system without refractive lenses

We present a lensless, interferenceless incoherent digital holography technique based on the principle of coded aperture correlation holography. The acquired digital hologram by this technique contains a three-dimensional image of some observed scene. Light diffracted by a point object is modulated using a random-like coded phase mask (CPM) and the intensity pattern is recorded and composed as a point spread hologram (PSH). A library of PSH is created using the same CPM by moving the pinhole to all possible axial locations. Intensity diffracted through the same CPM from an object placed within the axial limits of the PSH library is recorded by a digital camera. The recorded intensity this time is composed as the object hologram. The image of the object at any axial plane is reconstructed by cross-correlating the object hologram with the corresponding component of the PSH library. The reconstruction noise attached to the image is suppressed by various methods. The reconstruction results of multi-plane and thick objects by this technique are compared with regular lens-based imaging.

physics.optics↗