Mid-wave infrared (MWIR) spectral imaging is a powerful technique for regional-scale gas detection, however, existing instruments suffer from bulky volume, long scanning time, and complex structures which impede their practical deployment. This necessitates the development of lightweight, high-efficiency MWIR spectral imaging techniques tailored to gas monitoring scenarios. To address these challenges, a snapshot-compatible MWIR computational spectral imaging method based on dictionary learning and sparse reconstruction is proposed. The broadband thin-film filters with high transmittance in the target band are employed for spectral compressed measurements, and the corresponding encoded images are captured by the detector. Subsequently, the orthogonal matching pursuit algorithm is utilized for spectral reconstruction, enabling the efficient recovery of the target spectral data cube. To ensure the accurate reconstruction ofMWIRgas absorption characteristics, a phased dictionary construction strategy is designed, comprising basic dictionary learning and MWIR feature enhancement. The simulation reconstruction results for blackbody radiation spectra, non-training smooth spectra, and absorption spectra of 4 typical gases verify the feasibility of the proposed method. Experiments are conducted based on sequential simulation of the proposed snapshot architecture. For real-world spectral reconstruction tests, the method achieves a peak signal-to-noise ratio (PSNR) greater than 26.336 dB and a spectral angle mapper (SAM) less than 0.157. These results confirm the effectiveness of the proposed method, which provides a feasible technical solution for the development of lightweight MWIR spectral imaging systems for gas detection applications.

Weakly coupled resonators (WCRs) predicated on the mode localization phenomenon have found widespread utility in the topological design of high-performance sensors. However, the pronounced non-linearity derived from the loci veering around the zero point imposes a significant constraint on the measurement range of mode-localized sensors. This paper introduces a novel single-port readout circuit aimed at realizing full-scale linear sensing for mode-localized sensors. In our proposed methodology, we employ not only the conventional frequency closed-loop control but also introduce an amplitude closed-loop system incorporating automatic gain control (AGC). This AGC-based approach is utilized to maintain the amplitude product of resonant units at a standardized value. Consequently, we can consider the difference of squared amplitudes as the sensor output, which serves to effectively capture and characterize the fluctuations in external input signals. Furthermore, we have applied our proposed readout circuit to test a prototype of a micro-electro-mechanical system (MEMS) mode-localized accelerometer. The experimental results unequivocally affirm that the tested accelerometer prototype achieves linear sensing throughout the entire measurement range. Remarkably, it demonstrates a mechanical sensitivity of 0.1182 /g, coupled with a maximum non-linearity of -6.54%, and a bias stability of 19.23 mg, alongside a noise floor of 1.022 × 10 ^-4 V/Hz ^1/2 . These outcomes align closely with the output metric based on the subtraction of reciprocal amplitude ratios (SRAR). Our proposed methodology not only facilitates full-scale linear sensing for mode-localized sensors but also streamlines the signal extraction process, all while preserving the electromechanical performance. This advancement holds significant promise for the expansion of the application landscape for mode-localized sensors.

In order to eliminate the influence of the high-order magnetic dipole modes in the short-wave range of the high-refractive-index dielectric grating, we propose a thin film filter to cut off the “useless” short-wave. In this way, the high-order magnetic dipole can be suppressed, and the quality of the structure color is highly improved after the thin film filter cut off the incident light in the non-resonant band. The combined application of the thin film filter and the grating filter not only avoids the problem of too big film layer thickness, but also reduces the manufacturing process cost. For example, the film system (basic film system 0.5 L H 0.5 L) and thickness of green, 15° and 45° incident film filters are 21 layers, 1.76 μm and 41 layers, 4.02 μm. The color coordinates corresponding to the calculation results occupy a large area on the Commission Internationale de l’Eclairage 1931 (CIE 1931) chromaticity diagram, which proves that this design scheme can effectively improve the structural color quality. This method obtains excellent theoretical simulation results. This has important implications for high-end imaging equipment and sensors.

The deep-sea photogrammetry is an important means of deep-sea exploration. Due to the attenuation of light in water, deep-sea camera systems need deep-sea lamps to provide the light source, which consume lots of energy. So the light utilization efficiency of deep-sea optical camera affects the load capacity and operation capacity of deep-sea platforms. In addition, due to the non-linearity of light attenuation in different wavelength, the deep-sea optical images generally suffer from color deviation with tending to be blue and green, which leads to the decline of operation efficiency and the increase of scientific research cost in deep-sea exploration. In order to improve the light utilization efficiency and enhance the color restoration of deep-sea camera, we proposed, designed and developed a deep-sea camera with three detectors based on triple-prism (TD&TP-DSC) for the first time. In this camera system, three detectors combined with triple-prism aimed to improve the light utilization efficiency, and the coatings on the triple-prism were designed for gating waveband to improve the color restoration. With carrying out a series of experiments in water tank, water pool, Qiandao Lake and the South China Sea, the low-light performance and color restoration of TD&TP-DSC were certified. The experimental result showed that TD&TP-DSC had advantages over the common deep-sea camera, which provided enlightenment for the development of new generation deep-sea camera system.

The predecessor of China Optics was China Optics and Applied Optics Digest, which was founded in 1985. At that time, it was the only retrieval journal in the field of optics in China. At the end of 2008, China Optics and Applied Optics Digest was renamed 《中国光学》的前身是1985年创办的《中国光学与应用光学文摘》，当时是国内光学领域唯一的检索刊物。2008年底《中国光学与应用光学文摘》转型更名为《中国光学与应用光学》期刊，刊载内容突破了文摘的限制，正式成为学术刊物。