The skin is the largest organ of the human body, which plays an important role in barrier function, immune response, preventing water loss and excreting waste. Patients with large-scale severe skin injuries will die due to lack of adequate skin grafts. The development of 3D bioprinting technology provides a solution for the manufacture of transplantable skin. Firstly, the principles of skin wound repairing are described. Secondly, the bioinks, cells and main 3D bioprinting technologies used in skin wound repairing are compared. Then, the opto-electronic technologies involved are analyzed, and the challenges and future development of 3D bioprinting in the application of skin repair are summarized. Finally, the application requirements of opto-electronic technology in 3D bioprinting are proposed.

The master, which contains the desired optical surface, is epoxied to the substrate. When the pieces are separated, the epoxy resin layer is transferred to the substrate producing a replicated mirror. Epoxy replication is an efficient and low-cost way to fabricate optical mirrors. The surface figure accuracy will decrease with the increase in mirror size due to the characteristic of the epoxy resin, and there is no effective way to correct the surface figure aberrations after replication. Finite element analysis was used to simulate the replication process and optimize the thickness of the master for better surface figure accuracy. A multilayer film compatible with Magneto-Rheological Finishing was also developed. A parabolic replicated mirror with a diameter of Φ180 mm and a plane replicated mirror with a diameter of Φ500 mm were fabricated within 5 and 10 days, respectively. The precision shape (RMS<20 nm) and low surface roughness (Rq=0.6 nm) were both achieved.

Multi-line LiDAR has a wide range of application demands, but the current detection and processing circuit of LiDAR is mostly composed of discrete components, and the detector is separated from the processing circuit, which brings high cost, poor reliability, and other problems. To solve the above problems, an integrated 16-element LiDAR analog front-end micromodule based on system-in-package technology is proposed, which has important practical significance for the research of multi-component LiDAR micromodule. This module integrates a 16-element avalanche photon diode array detector, a self-developed multi-channel LiDAR analog front-end readout circuit chip, a temperature sensor, and a thermoelectric cooler, etc., which can realize the integration of detection, processing and temperature control. The test results show that the thermostatic stability of the micromodule is 0.07 ℃, the bandwidth of the micromodule is up to 190 MHz, the noise level of the integrated micromodule is reduced by more than 32% compared with that of the non-integrated micromodule, and high speed detection of 5 ns laser narrow pulse is realized.

Due to the small scale and weak energy of the infrared dim small target, the background must be suppressed to enhance the target in order to ensure the performance of detection and tracking of the target in the later stage. In order to improve the ability of gradient reciprocal filter to suppress the clutter texture and reduce the interference of the residual texture to the target in the difference image, an adaptive gradient reciprocal filtering algorithm(AGRF) is proposed in this paper. In the AGRF, the adaptive judgment threshold and the adaptive relevancy coefficient function of inter-pixel correlation in the local region are determined by analyzing the distribution characteristics and statistical numeral characteristic of the background region, clutter texture, and target. Then the element value of the adaptive gradient reciprocal filter is determined by combining the relevancy coefficient function and the gradient reciprocal function. Experimental results indicate that the sensitivity of the AGRF algorithm to the clutter texture is significantly lower than that of the traditional gradient reciprocal filtering algorithm under the premise of the same target enhancement performance. Compared with the other nine algorithms, the AGRF algorithm has better signal- to-noise ratio gain (SNRG) and background suppress factor (BSF).助项目(2019AC20147)

The strong localized plasmon resonance of metasurfaces makes the resonance frequency extremely sensitive to the dielectric environment, which can be applied to label-free environment detection. In this paper, a bow-tie terahertz metasurface with an optimized ratio of the quality factor to effective mode volume(Q/Veff) is designed. The unit cell of the proposed structure is composed of a mirror-symmetrical metallic bow tie in the middle and continuous metallic strips on both sides. The width of each metal strip and the length of the bow-tie gap are optimized for the parameter Q/Veff. When the metal strip width is 25 μm and the gap length is 2 μm, the effective mode volume is 3.6 μm3 and Q/Veff is 2.2 μm-3 at 0.7 THz. In the experiment, different concentration of the lead ion solution was dropped on the proposed metasurface. The transmission spectrum was measured by a terahertz time-domain spectroscopy system. The results showed that there is a linear relationship between resonance frequency shift and lead ion solution concentration from 0.1 ng/mL to 20 ng/mL. The detection limit is 0.1 ng/mL. The terahertz metasurface sensor has the advantages of the miniaturized size, easy sample preparation, fast measurement capability and real-time detection, which will be widely used in environmental protection and food safety.(2020190189)

A deep UV tunable narrow-passband light source module for the nitrate measurement system is proposed and demonstrated in this paper. The module consists of a deuterium lamp, an angle rotation stage, a motorized filter wheel, the deep UV optical filters with different central wavelengths, as well as the collimating lens. Seven UV filters with different central wavelengths of 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm and 280 nm are placed on the filter wheel. Based on the principle of multiple-beam interference, the central wavelength of the transmission light and the rotation angle are regressed and calibrated to obtain the relationship model. The experiment results demonstrate that with the rotation angle from 0 to 30°, each filter can realize wavelength tuning range of 10 nm. In addition, the designed deep UV tunable light source module can obtain monochromatic light with the wavelength ranging from 212 nm to 280 nm, which meets the measurement requirements of the nitrate in seawater.measurement