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http://dx.doi.org/10.1364/AO.8.000822 | DOI Listing |
Zhongguo Yi Liao Qi Xie Za Zhi
November 2024
College of Optical Science and Engineering, Zhejiang University, Hangzhou, 310027.
This article introduces a high-magnification electronic endoscope system that utilizes a continuous zoom optical design, enabling high-magnification imaging at the cellular level. By selecting an appropriate initial retrofocus structure, the optimized modulation transfer function (MTF) curve of the zoom objective lens approaches the diffraction limit. Additionally, the tip and operation parts of the system incorporate modular gas-tight sealing and multiple layers of protective structure.
View Article and Find Full Text PDFBackground: Cardiac computed tomography (CT) exams are some of the most complex CT exams due to the need to carefully time the scan when the heart chambers are near the peak contrast concentration. With current "bolus tracking" and "timing bolus" techniques, after contrast medium is injected, a target vessel or chamber is scanned periodically, and images are reconstructed to monitor the opacification. Both techniques have opportunities for improvement, such as reducing the contrast medium volume, the exam time, the number of manual steps, and improving the robustness of correctly timing the peak opacification.
View Article and Find Full Text PDFDue to the large size of an automobile headlamp that has a laser as the light source, it is difficult to reflect the advantages of high laser brightness into the effect of automobile illumination, so it has not been promoted. We propose a laser headlamp system that integrates low-beam and high-beam structures with superior illumination effects (longer illumination distance and wider illumination range) by designing freeform optical components and optical structure. The small-volume headlamp can meet the requirements of the Economic Commission for Europe regulation (ECE) R112.
View Article and Find Full Text PDFSensors (Basel)
July 2023
Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China.
The near-space atmosphere is thin, and the atmospheric refraction and scattering on optical observation is very small, making it very suitable for wide-area and high-resolution surveillance using high-altitude balloon platforms. This paper adopts a 9344 × 7000 CMOS sensor to obtain high-resolution images, generating large-field-of-view imaging through the swing scanning of the photoelectric sphere and image stitching. In addition, a zoom lens is designed to achieve flexible applications for different scenarios, such as large-field-of-view and high-resolution imaging.
View Article and Find Full Text PDFPhotoacoustics
June 2023
Institute of Applied Physics, Russian Academy of Sciences, 46 Ulyanov Str., Nizhny Novgorod 603950, Russia.
A number of optoacoustic (or photoacoustic) microscopy and mesoscopy techniques have successfully been employed for non-invasive tumor angiography. However, accurate rendering of tortuous and multidirectional neoplastic vessels is commonly hindered by the limited aperture size, narrow bandwidth and insufficient angular coverage of commercially available ultrasound transducers. We exploited the excellent flexibility and elasticity of a piezo polymer (PVDF) material to devise a fisheye-shape ultrasound detector with a high numerical aperture of 0.
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