Image aberrations caused by acousto-optic (AO) anisotropic diffraction in uniaxial crystals are discussed. For their analysis, we propose a simplified ray-tracing model of an AO crystal cell (AOC). With this approach, one can assign any configuration of AO interaction, any material and geometry of the crystal, and then estimate all conventional ray aberrations, such as spherical, coma, astigmatism, distortion, etc. The optimization procedure is demonstrated by the aberration analysis of three principal spectral imaging schemes based on AO tunable filters (AOTFs). The approach developed promises performance improvement of AOTF-based systems for high-quality spectral imaging and image processing.

We present, to the best of our knowledge, the first experimental demonstration of a new imaging system for in situ measurement of the two-dimensional (2D) distribution of the surface temperature of microscopic specimens. The main component of the system is an imaging tandem acousto-optical tunable filter (TAOTF) synchronized with a video camera. A set of TAOTF spectroscopic images (up to a few hundreds) is taken by the TAOTF imaging system to fit the measured spectral curves in each pixel to the Planck radiation function and determine the temperature and emissivity of the sample using the gray body approximation. It is experimentally shown that this technique provides aberration-free spectral imaging suitable for precise multispectral imaging radiometry (MIR).

The problem of in vivo photoluminescence diagnostics of the tissues accessible by endoscopes is discussed. The spectral imaging module attachable to conventional rigid and°exible medical endoscopes is developed and described. It is based on a double acousto-optical tunable¯lter (AOTF) and a specialized optical coupling system. The module provides wide¯eld of view (FOV), absence of image distortions, random spectral access, fast spectral image acquisition at any wavelength in the visible range and accurate measurement of re°ectance spectrum in each pixel of the image. Images of typical biomedical samples are presented and discussed. Their spectra are compared to the reference data.

We report on the noninvasive method for in vivo study of fish's cardiovascular system, that is, the heart and the structure of vessels that carry blood throughout the body. The proposed approach is based on combined photoplethysmographic and videocapillaroscopic microscopic imaging and enables noncontact two‐dimensional mapping of blood volume changes. We demonstrate that the obtained data allows precise measurements of heartbeat, blood flow velocity and other important parameters (see Videos S1 and S2). To validate the developed image processing technique, we have carried out multiple experiments on zebrafish—a well‐proven informative model organism widely used to understand cardiac development. The proposed approach may be effective for the study of cardiovascular system formation and functioning as well as the impact of various influencing factors on them.

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The problem of creating a hyper spectral optoelectronic system for observing natural and artificial objects by means of unmanned aerial vehicles (UAV) is considered. The structure and composition of the system that solves this problem are described. It is based on acousto-optic filters. The results of laboratory testing of the hyper spectrometer are presented.

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Optical biomedical imaging in short wave infrared (SWIR) range within 0.9–1.7 μm is a rapidly developing technique. For this reason, there is an increasing interest in cost-effective and robust hardware for hyperspectral imaging data acquisition in this range. Tunable-filter-based solutions are of particular interest as they provide image processing flexibility and effectiveness in terms of collected data volume. Acousto-optical tunable filters (AOTFs) provide a unique set of features necessary for high-quality SWIR hyperspectral imaging. In this paper, we discuss a polarizer-free configuration of an imaging AOTF that provides a compact and easy-to-integrate design of the whole imager. We have carried out image quality analysis of this system, assembled it and validated its efficiency through multiple experiments. The developed system can be helpful in many hyperspectral applications including biomedical analyses.