Weibiao Wang

To overcome the limitations of complex dispersion structures, low diffraction efficiency at band edges, and continuous spectral aliasing in dispersion-interference coupled static Fourier transform spectrometers operating in the 3–5 μm mid-infrared band, a compact bandpass sampling Fourier transform spectrometer based on a horizontal roof mirror and a segmented blazed grating with differentiated blaze angles (HRMSG-FTS) and a stepwise continuous spectrum reconstruction method (SCSR) were proposed. The HRMSG-FTS integrates dispersion and compensation through dual-pass coupling of the segmented blazed grating and the horizontal roof mirror, thereby reducing system complexity and improving diffraction efficiency at the band edges. Simulation results show that the HRMSG-FTS achieves a spectral resolution of 0.625 cm⁻¹ while significantly reducing the longitudinal system size, and improves diffraction efficiency at the band edges by more than 20% compared with a single-blaze-angle grating. To mitigate continuous spectral aliasing, the SCSR method progressively decouples and accurately reconstructs the aliased spectrum. Simulations show that the reconstruction error coefficient is reduced from 0.683 to 0.031, and the effectiveness of SCSR is verified experimentally. The proposed system and method combine compactness with high accuracy and are suitable for applications such as airborne atmospheric monitoring, industrial gas detection, and portable infrared spectral analysis.

In this work, a broadband polarization-sensitive metamaterial absorber (MA) based on a plasmonic bilayer nanostructure array is designed and numerically investigated. The proposed polarization-sensitive MA exhibits a high average absorption of 91.9% for TM-polarized light from 500 nm to 2000 nm and as low as 11.6% for TE-polarized light. Furthermore, a plasmonic germanium photodetector (PD) functionalized by the proposed polarization-sensitive MA is constructed and the potential application of distinguishing TM- and TE-polarized light is explored in simulation. The calculated results demonstrate that the photo-current difference generated by the PD under TM- and TE-polarized light excitation can reach 11.9 μA. The proposed broadband polarization-sensitive MA can be used in many fields, including polarization detection and other polarization-sensitive optoelectronic devices.

Photodetectors with broad spectral response and high responsivity demonstrate significant potential in optoelectronic applications. This study proposes a Si/Ge avalanche photodiode featuring nanostructures that enhance light absorption. By optimizing the device epitaxial structure and these nanostructures, a wide spectral responsivity from 0.4 to 1.6 μm is achieved. The results demonstrate that introducing surface photon-trapping nanoholes and SiO₂ reflective grating nanostructures increases the average light absorptivity from 0.64 to 0.84 in the 0.4–1.1 μm range and from 0.31 to 0.56 in the 1.1–1.6 μm range. At an applied bias of 0.95 V_br-apd, the responsivity reaches 17.24 A/W at 1.31 μm and 17.6 A/W at 1.55 μm. This research provides theoretical insights for designing high-responsivity photodetectors in the visible–near-infrared broadband spectrum.

Infrared multispectral imaging technology can achieve the long-distance, wide-ranging and fast detection of target gas, and has been widely used in the fields of dangerous-gas detection and environmental monitoring. However, due to the difficulty in acquiring background radiation as well as atmospheric disturbance and noise interference in the detection process, the quantitative detection of gas concentration has become a difficult problem to solve. Therefore, this paper proposes an inversion method for gas column concentration based on infrared multispectral imaging technology. Firstly, infrared background radiation images of the non-target gas absorption spectrum band were collected and converted into background radiation images of the target gas absorption spectrum band according to the dual-channel mapping relationship. Then, combined with the gas radiation images of the target gas absorption spectrum band, the column concentration distribution of the gas was obtained by using the measured calibration relationship between absorbance and column concentration. Experiments of gas detection in different environments were carried out, and the column concentration distribution of the target gas was inverted using this method; the results showed that the average relative error of the inversion of the gas column concentration was 4.84%, which enables the quantitative detection of gas column concentration in a complex environment.

In order to solve the problems of a low target recognition rate and poor real-time performance brought about by conventional infrared imaging spectral detection technology under complex background conditions or in the detection of targets of weak radiation or long distance, a kind of infrared polarization snapshot spectral imaging system (PSIFTIS) and a spectrum information processing method based on micro-optical devices are proposed in this paper, where the synchronous acquisition of polarization spectrum information is realized through the spatial modulation of phase with a rooftop-shaped multi-stage micro-mirror and the modulation of the polarization state of light with a micro-nanowire array. For the polarization interference image information obtained, the infrared polarization spectrum decoupling is realized by image segmentation, optical path difference matching, and image registration methods, the infrared polarization spectrum reconstruction is realized by Fourier transform spectral demodulation, and the infrared polarization image fusion is realized by decomposing and reconstructing the high- and low-frequency components of the polarization image based on the Haar wavelet transform. The maximum spectral peak wavenumber error of the four polarization channels of the polarization spectrum reconstruction is less than 2 cm⁻¹, and the polarization angle error is within 1°. Ultimately, compared with the unprocessed polarization image unit, the peak signal-to-noise ratio is improved by 45.67%, the average gradient is improved by 8.03%, and the information entropy is improved by 56.98%.

The use of a dual-interference channels static Fourier transform imaging spectrometer based on stepped micro-mirror (D-SIFTS) for environmental gas monitoring has the advantages of high throughput, a compact structure, and a stable performance. It also has the characteristics of both a broad spectral range and high spectral resolution. However, its unique structural features also bring many problems for subsequent data processing, mainly including the complex distribution of the interference data, the low signal-to-noise ratio (SNR) of infrared scene images, and a unique inversion process of material information. To this end, this paper proposes a method of image and spectra information processing and gas concentration inversion. A multiscale enhancement algorithm for infrared images incorporating wavelet denoising is used to obtain high-quality remote sensing scene images, and spectral reconstruction optimization algorithms, such as interference intensity sequence resampling, are used to obtain accurate spectral information; the quantitative calibration model of the detected gas concentration is established to achieve high-precision inversion of gas concentration, and its distribution is visualized in combination with the scene image. Finally, the effectiveness and accuracy of the data processing algorithm are verified through the use of several experiments, which provide essential theoretical guidance and technical support for the practical applications of D-SIFTS.

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。

To improve the low responsivity of the silicon avalanche photodiode in the near-ultraviolet wavelength range, we designed a near-ultraviolet highly responsive Si-APD basic structure with a multiplication layer neighboring the photosensitive surface through the analysis of the optical absorption characteristics, junction breakdown characteristics, and avalanche multiplication characteristics. The dark current and electric field distribution of the device were investigated. Meanwhile, the structural parameters of the surface non-depleted layer, multiplication layer, and absorption layer were optimized. It was found that the breakdown voltage of the device is 21.07 V. At an applied bias voltage of 20.02 V, the device exhibits a responsivity of 6.79–14.51 A/W in the wavelength range of 300–400 nm. These results provide valuable insights for the design of silicon avalanche photodiode with high responsivity in the near-ultraviolet range.

In this study, a dual-color patterned perovskite quantum dot color conversion layer with a light-blocking matrix was created by combining laser drilling with micropore filling technology. When the blue micro-LED and the quantum dot color conversion layer make contact, the fluorescence crosstalk effect can be simulated to be near zero. The color conversion layers with high color gamut (111.2% of the National Television System Commission) were further confirmed to have outstanding optical isolation performance through experimental observations. This work may have significant advantages for its applications in photonic integration, micro-LED, and near-field displays due to simple operation process, maskless, harmlessness to quantum dots, short process period, and low crosstalk effect.