A method for registering a visual image and a spectral image of a biological sample includes aligning a first set of coordinate positions of a plurality of reticles on a slide holder and a second set of coordinate positions of the plurality of reticles on the slide holder. The method further includes generating a registered image of a visual image of a biological sample and a spectral image of the biological sample based upon the alignment of the first and second set of coordinate positions.

Method for analyzing biological specimens by spectral imaging

Self-interference holography is a common technique to record holograms of incoherently illuminated scenes. In this review, we survey the main milestones in the topic of self-interference incoherent digital holography from two main points of view. First, we review the prime architectures of optical hologram recorders over more than 50 years. Second, we discuss some of the key applications of these recorders in the field of imaging in general, and for 3D super-resolution imaging, fluorescence microscopy, partial aperture imaging, seeing through a scattering medium, and spectral imaging in particular. We summarize this overview with a general perspective on this research topic and its prospective directions.

Recent advances in self-interference incoherent digital holography

Interferenceless coded aperture correlation holography (I-COACH) is an incoherent digital holography technique for imaging 3D objects without two-wave interference. In I-COACH, the object beam is modulated by a pseudorandom coded phase mask (CPM) and propagates to the camera where its intensity pattern is recorded. The image of the object is reconstructed by a cross-correlation of the object intensity pattern with a point intensity response of the system, whereas the light from both the object and the point, are modulated by the same CPM. In order to recover the image of the object without bias level and background noise, multiple intensity recordings are necessary for both objects as well as the point object, which in turn significantly reduces the time resolution of imaging. In this study, a non-linear reconstruction technique is developed to reconstruct the image of the object with only a single camera shot. Furthermore, the proposed technique is adaptive to different experimental conditions in the sense of finding different optimal parameters for each experiment. The new method has been implemented on a regular I-COACH system in both transmission as well as reflection illumination modes.

Non-linear adaptive three-dimensional imaging with interferenceless coded aperture correlation holography (I-COACH).

Interaction of intense lasers with solid materials offers an alternative way to achieve high-order harmonic generation (HHG). Since the underlying mechanisms of the harmonic emission remain uncerta...

https://www.tandfonline.com/doi/pdf/10.1080/23746149.2018.1562982

High order harmonic generation in solids: a review on recent numerical methods

A hologram recording method for recording information of signal light as holograms in an optical recording medium, which includes illuminating signal light at the optical recording medium; illuminating reference light at the optical recording medium simultaneously with the signal light such that an interference pattern is formed by the signal light and the reference light intersecting in the optical recording medium; and shifting a region in the optical recording medium at which the signal light and the reference light intersect, by shifting an illumination position of the reference light along an optical axis of the signal light, thereby recording a plurality of holograms in the recording medium.

Hologram recording method and hologram recording device

Single-shot phase-shifting incoherent digital holography with multiplexed checkerboard phase gratings is proposed for acquiring holograms of moving objects. The gratings presented here play the following three roles: dividing the beams, modulating the curvature of spherical beams, and introducing different phase shifts. With the gratings of our proposed method, four individual holograms of a spatially incoherent light are formed on an image sensor. Therefore, it is possible to simultaneously capture four holograms and implement a phase-shifting technique. A proof-of-principle experiment was conducted to show the feasibility of the proposed method.

Single-shot phase-shifting incoherent digital holography with multiplexed checkerboard phase gratings.

Although three-dimensional (3D) imaging and extended depth-of-field (DOF) imaging are completely opposite techniques, both provide much more information about 3D scenes and objects than does traditional two-dimensional imaging. Therefore, these imaging techniques strongly influence a wide variety of applications, such as broadcasting, entertainment, metrology, security and biology. In the present work, we derive a generalised theory involving incoherent digital holography to describe both 3D imaging and quasi-infinite–DOF (QIDOF) imaging, which allows us to comprehensively discuss the functions of each imaging technique. On the basis of this theory, we propose and develop a bimodal incoherent digital holography system that allows both 3D imaging and QIDOF imaging. The proposed system allows imaging objects using spatially incoherent light and reconstructing 3D images or QIDOF images solely by changing the phase pattern of a spatial light modulator and without requiring mechanical adjustments or any other modifications to the setup. As a proof-of-principle experiment, we evaluate the DOF and record holograms of a reflective object with the proposed system. The experimental results show that the generalised theory is effective; our demonstration platform provides the function of 3D and QIDOF imaging.

/pdf/bimodal-incoherent-digital-holography-for-both-three-ae8uzcds1p.pdf

Bimodal Incoherent Digital Holography for Both Three-Dimensional Imaging and Quasi-Infinite-Depth-of-Field Imaging.

To increase the reproduced data transfer rate in holographic memory, we have investigated simultaneous reproduction of two data pages. By irradiating s- and p-polarization reference beams whose angle gap is equal to the angle between the neighboring data pages in angle-multiplexed holograms, two different data pages can simultaneously be reproduced with a bit error rate low enough to decode. This technology is effective to double the data transfer rate in holographic memory.

Dual-page reproduction to increase the data transfer rate in holographic memory.

We developed an integrated simulation technique for volume holographic memory. Volume holographic gratings were expressed as the permittivity distribution in the media. The distribution derived from the interference fringes of a reference beam and an object beam. These fringes were calculated using the angular spectrum of plane waves, instead of the diffraction integral formula. The finite-difference time-domain method was used to simulate the light wave propagation in the volume holographic gratings. The diffracted electromagnetic waves on the observation plane were obtained by the irradiation of the reference beam from the source plane. The simulation of an angularly multiplexed hologram was performed. The simulation results showed that two different data pages are reproduced separately at the same angle as those recorded in a numerical computation.

Integrated Simulation Technique for Volume Holographic Memory Using Finite-Difference Time-Domain Method

Incoherent digital holography (IDH) enables passive 3D imaging under spatially incoherent light; however, the reconstructed images are seriously affected by detector noise. Herein, we derive theoretical sampling requirements for IDH to reduce this noise via simple postprocessing based on spatial averaging. The derived theory provides a significant insight that the sampling requirements vary depending on the recording geometry. By judiciously choosing the number of pixels used for spatial averaging based on the proposed theory, noise can be reduced without losing spatial resolution. We then experimentally verify the derived theory and show that the associated adaptive spatial averaging technique is a practical and powerful way of improving 3D image quality.

Nobuhiro Kinoshita

Papers

Single-shot phase-shifting incoherent digital holography with multiplexed checkerboard phase gratings.

Bimodal Incoherent Digital Holography for Both Three-Dimensional Imaging and Quasi-Infinite-Depth-of-Field Imaging.

Dual-page reproduction to increase the data transfer rate in holographic memory.

Integrated Simulation Technique for Volume Holographic Memory Using Finite-Difference Time-Domain Method

Sampling requirements and adaptive spatial averaging for incoherent digital holography.