The problems of radiation damage suffered by the CMOS image sensors (CISs) in space radiation or nuclear radiation environments have been paid much attention. The simulation researches of the CIS will be helpful to reveal the mechanism of radiation damage in the CISs, and then develop the radiation-resistant reinforced design, so as to improve the ability of the radiation resistance of the CISs. The simulation research progress of radiation damage effects in the CISs at home and abroad was briefly introduced. Combining the radiation effect simulation of the electronic components with a lot of practical experience in radiation experiments developed by the project team, the simulation methods of radiation damage effect in the CISs were discussed in the aspects of device physical modeling, clock driving circuit modeling, radiation damage effect modeling and simulation results verification. The key problems that need to be solved in the simulation researches of radiation damage effects in the CISs were analyzed and summarized.

A pinhole-coupled dual-channel terahertz waveguide directional coupler was proposed. It adopted a novel ladder structure and combined two single-channel couplers to achieve the same coupling output in two channels. The research results show that in the frequency range of 180~260GHz, the coupling degree of the coupler is 10dB, the maximum output error is less than 1.6dB, the return loss is greater than 25dB, the isolation degree is greater than 35dB, and the relative bandwidth is 36%. Compared with the traditional terahertz waveguide directional coupler, this coupler can realize dual-channel coupling output, and can be used for dual-channel power detection, power synthesis and distribution in terahertz systems.

Aiming at the requirements of avalanche photodiode (APD) focal plane in 3D-lidar imaging, a 2×128 silicon linear-mode APD focal plane module was prepared. It consisted of silicon based APD focal plane array, readout circuit and refrigeration package shell. APD pixels adopted the reach-through structure, achieved a high fill factor by large size micro-lens arrays, realized crosstalk suppression through isolation ring doping, and achieved breakdown voltage and response current uniformity through optimization of the ion implantation process. A low noise transimpedance amplifier circuit with large bandwidth and a high precision timing circuit were designed to realize narrow pulse width and high sensitivity detection. Airtight encapsulation was performed to achieve integrated APD focal plane refrigeration encapsulation with a refrigeration temperature difference over 40K. The test results show that the detection threshold optical power of the focal plane can reach 3.24nW, and the response non-uniformity is 3.8%, the crosstalk is 0.14%, and the minimum time resolution can reach 0.25ns, realizing the simultaneous output function of intensity information and time information.

Indium gallium zinc oxide thin film transistors (IGZO-TFT) were prepared by aqueous solution method, and the effects of different post-annealing temperatures (270, 300, 330, 360 and 400℃) on the electrical properties of IGZO-TFT devices with and without UV-assisted annealing conditions were investigated. It is found that the IGZO-TFT exhibites the best device electrical properties at the post-annealing temperature of 360℃, thus demonstrating that the aqueous solution method can prepare IGZO-TFTs at low temperatures of less than 400℃. Meanwhile, it is shown that at a post-annealing temperature of 360℃, compared with the non-UV-assisted annealed IGZO-TFT, the saturation mobility of the UV-assisted annealed IGZO-TFT increases from 1.19 to 1.62cm2/Vs, and the positive gate bias offset decreases from 8.7 to 4.6V and the negative gate bias offset decreases from -9.7 to -4.4V, thus demonstrating that UV-assisted annealing has activating and passivating effects on IGZO films, which can optimize the electrical properties of IGZO-TFT devices.

Aiming at the requirements of high precision and low power consumption for CMOS image sensor, a 14bit column-level ADC was proposed. Based on the architecture of RAMP ADC, the two-step structure composed of 3-bit SAR ADC and 11-bit RAMP ADC was adopted, which reduced the quantization time effectively. In the module of RAMP ADC, the high-low clock counting method was employed to reduce the power consumption in the counting part. The correlated double sampling logic of RAMP-SAR-RAMP switch was proposed, which could decrease the number of SRAM and further reduce the layout area. Simulation results based on the 0.18μm standard CMOS process show that under the working mode of 600MHz clock and single edge counting, the quantization time of ADC is 9.32μs, and the average power consumption in the counting part is 8.51μW under the 1.8V digital power supply.

A miniaturized low-frequency FBG acceleration sensor based on symmetric cantilever beam was proposed. Firstly, the sensitivity and natural frequency expressions of the sensor were derived according to the mechanical model of the sensor structure. Then, the structural parameters of the sensor were optimized, and the static stress and modal analysis of the sensor were carried out by ANSYS Workbench. Finally, the sensor was made according to the analysis results, and its amplitude-frequency response, sensitivity characteristics, transverse anti-interference ability and impact response were studied through experiments. The experimental results show that the natural frequency of the sensor is 72Hz, the sensitivity is 681.7pm/g, the lateral interference resistance is less than 4.9%, and the volume is only 6.48cm3, which can be used for real-time monitoring of low frequency weak vibration signals below 50Hz.

Based on the square ring monopole antenna element, an ultra wideband circularly polarized microstrip array antenna in terahertz band was designed. By changing the structure of the ring antenna element, the current on the antenna surface could flow asymmetrically, and the circularly polarized wave radiation could be realized by changing the aspect ratio of the current using triangular perturbation. Using 2×4 antenna array not only increased the gain of the antenna, but also optimized the directional characteristics of the antenna. The simulation results show that the antenna array operates at 193.86~391.02GHz, the relative bandwidth is 67.42%, and the maximum gain can reach 15dBi. It has a good application prospect in terahertz communication.

A highly sensitive fiber optic Mach-Zehnder strain sensor based on vernier effect was proposed and prepared. The sensor consisted of two Mach-Zehnder interferometers with similar free spectral ranges connected in parallel. The single Mach-Zehnder interferometer was made by splicing a section of no-core fiber and a section of few-mode fiber between two single-mode fibers. Two Mach-Zehnder interferometers with similar but unequal free spectral ranges were superimposed in parallel to produce the vernier effect to achieve the effect of increased sensitivity. The experimental results show that the strain sensitivity of the single interferometer is -1.90pm/με in the strain range of 0~166.667με, and the strain sensitivity of the envelope of the superimposed spectrum of two interferometers in parallel is 12.06pm/με in the strain range of 0~166.667με. This sensing system adopts parallel connection to realize the vernier effect, which has the advantages of simple fabrication, high flexibility and high sensitivity, and can be widely used in the field of precision measurement.

For the existing bridge deformation detection methods based on fiber optic gyroscope (FOG) cannot eliminate the path deviation caused by the yaw of the detection trolley, a deformation detection method of rail steel bridge based on FOG was proposed. Firstly, the principle and system architecture of FOG measurement of bridge alignment were explained. Then the steel structure under rail condition was analyzed by finite element method. By setting different temperature gradients, it was verified that the deformation of the rail was linear with the temperature, and the error model of rail and temperature was established. Finally, the validity of the method was verified by setting up the test environment to test the rail alignment and the rail deformation at different temperatures. The experimental results show that the relationship between the deformation of rail steel bridge and the ambient temperature is 1~2mm/10℃, which provides a temperature error calibration model for subsequent actual bridge deformation measurement. The precision of deformation detection of rail steel bridge based on FOG is better than 2mm.

InPBi exhibits a strong and broad photoluminescence spectrum at room temperature. The broad spectrum originates from the PIn antisite and Bi-related deep levels. This optical property makes InPBi promising for super-radiative light source in optical coherence tomography system (medical imaging technology). TEM and APT were used to discuss the structural property of InPBi thin films. The results show that Bi atoms distributes quite non-uniform in InPBi thin films. There is a Bi-rich region at the InPBi/InP interface. Besides, there is a Bi nano-wall in (110) face along the ［001］. This enriched distribution of Bi atoms inhibits the carrier recombination processes in relation to PIn antisite deep level. This work provides theoretical basis for fabricating super-radiative light-emitting diodes applied in optical coherence tomography system.

In the homoepitaxial growth of silicon carbide (4H-SiC) by chemical vapor deposition (CVD), the distribution of its temperature field is crucial for the quality of the epitaxial layer. The CVD temperature field was simulated and experimentally verified using on-axis 4H-SiC homogeneous epitaxy. It is found that the 3C-SiC crystal polytype inclusions in the on-axis 4H-SiC epitaxial layers are closely related to the temperature field distribution in the growth chamber. The results validate the simulation with a high degree of consistency in above two′s temperature distributions, which also verify the accuracy of the simulation data.

Through theoretical simulation and fabrication, the performance of optical amplification chip based on asymmetric quantum-wells(10nm and 6nm mixed quantum-wells)and symmetric quantum-wells (10nm quantum-wells) was analyzed and compared. The theoretical mode gains of the two structures were in good agreement with the measured results. The final spectral test results show that the fundamental state gain saturation exists in the symmetric quantum-wells optical amplification chip. The excited state transition dominates in the case of large current injection, resulting in a sharp decrease in the spectral bandwidth. With the increase of injection current, spectral width of asymmetric quantum-wells optical amplification chip is widened constantly. The optical bandwidth of 199.7nm is achieved at 600mA, covering the S+C bands. Therefore, the asymmetric quantum well structure is more conducive to the realization of high power and wide spectrum optical amplification chip.

After sampling the particle collision voltage signal in particle impact noise detection (PIND) test, the change trend of the parameters corresponding to the sampled data after the sample size increased was studied. It shows that the average value of ＞20mV sampling values tends to be stable, reflecting a certain statistical law. Considering the randomness of the particle collision process and the velocity attenuation trend, the hypothesis that the velocity change process can be regarded as a Poisson process in the velocity space was proposed, and the conjecture that the sampling value ＞20mV conforms to the exponential distribution was reached. For the combination of multiple particle types, particle positions and test frequencies, the probability density of exponential distribution obtained from this conjecture is consistent with the probability density obtained from sampled data, indicating that the hypothesis and its conjecture are valid, and the relationship between λ of exponential distribution and various factors is discussed. The obtained statistical model and the method used are instructive for the study of particle collision process and the characteristics of remainder.

Aiming at the problems of low resolution, narrow field of view and non-uniformity of traditional infrared array detector, a scanning imaging method based on infrared point detector was proposed. Firstly, a scanning mirror driven by a micro motor was used to obtain the infrared hot spots on the surface of the object, which were converged to the infrared point detector through the optical lens. Then the signal processing board collected and processed them to generate infrared grayscale image. Finally, a multi threshold segmentation pseudo-color mapping model was used to transform grayscale image into pseudo-color image. The experimental results show that the infrared point detector scanning imaging method can realize the large field of view and high-resolution imaging of the infrared scene, and the point detector has the advantages of simple manufacturing process and low cost. It effectively breaks the limitations of technical and cost constraints of the large planar array detector in the traditional high-resolution imaging system, and is more conducive to the promotion and application of the infrared imaging technology.

Aiming at WDM transmission of wideband RF signal in electronic warfare system, this paper gave the influence rule of key parameters in microwave photonic link on spurious signal through theoretical analysis, and put forward the optimization method of non-uniform channel spacing assignment. By fine-tuning the wavelength of each channel, the frequency of spurious signals generated by four-wave mixing exceeded the bandwidth of the EW receiver, so as to reduce the influence of spurious signals on the system. The scheme was simple to implement and had good engineering implementability without changing the existing electronic warfare system architecture. The experimental results show that, compared with the uniform wavelength intervals, when the 5-channel non-uniform WDM signals is transmitted for 1km, the spurious signals caused by four-wave mixing in the receiver bandwidth are significantly optimized, and the dynamic range is increased by more than 26dB.

Aiming at the problems of difficult detection of infrared small targets in cloudy background with few available data sets, a detection method based on chaos prediction was proposed. Based on the spatial chaotic characteristics of cloudy background, the prediction model of chaotic sequence was designed by using radial basis function neural network, and the network parameters were optimized by genetic algorithm to improve the prediction accuracy. Then, the small target detection was realized by the prediction error between the predicted and actual values of the image pixel sequence by the prediction model. Experiments verify the effectiveness of the above algorithm. The detection rate of test samples is 86.7% and the false alarm rate is 0.86%.

For the problems that the traditional phase-shifting interferometry required multiple interferograms, which thus required high stability of the measurement equipment, resulting in slow phase extraction, a phase solving method of two-frame random phase-shifting interferograms based on the special extremum feature of the interferogram was proposed. This method required only two-frame interferograms. The two-frame interferograms with random phase shifting were processed separately by Gaussian high-pass filter to filter out their backgrounds. Then the phase shifting between these two interferograms was determined by a certain number of special extremum feature pixels in the interferogram. Finally, the phase of the interferogram was calculated according to the phase-shifting phase extraction algorithm of the arctangent function. The comparison results of simulation and actual measurement show that this method can obtain high-precision measurement phase through two-frame random phase-shifting interferograms, greatly reducing the influence of measurement system errors on the phase solving results. For the 256×256pixels interferogram of the eye part of the plaster model, the execution time is within 0.02s, which is fast for phase extraction.

Aiming at the phenomena that there may be an error floor of quasi-cyclic low-density parity-check (QC-LDPC) codes in high signal-to-noise ratio (SNR) region, a novel construction method of irregular QC-LDPC codes based on eliminating elementary trapping sets(EETS) and girth constraints(GC) was proposed. The proposed method constructed the basic matrix by means of selecting the degree distribution dexterously and using the ETS search and girth constraints to modify the progressive edge growth (PEG) algorithm, and then obtained the final check matrix by means of expanding the arithmetic progression sequence (APS). Furthermore, only by simply searching and eliminating the ETS in the form of the simple cycles, the proposed method assured that the majority of the ETS in the set range do not exist in the constructed basic matrix, thus the error floor phenomenon was reduced. The proposed method could flexibly adjust and design the code-length and code-rate with relatively low complexity. The simulation results show that the error-correction performance of the irregular QC-LDPC code constructed by the proposed construction method, compared with the five QC-LDPC codes, is more superior and of no obvious error floor phenomenon.

In view of the lack of samples caused by the difficulty in obtaining crack images and the insufficient ability of traditional data expansion methods to enhance the sample feature space, a crack sample expansion method based on modified deep convolutional generative adversarial network (MDCGAN) was proposed. Firstly, the data set was preprocessed, and the sliding window method was used for data dimension reduction and cleaning. Secondly, the activation function was optimized to improve the diversity of generation features. At the same time, spectral normalization was introduced for weight standardization to improve the stability of network structure, so as to generate high-quality crack data set. Finally, the improved Alexnet network was used to extract and classify the extended mixed sample set. The results show that the data enhancement performance of MDCGAN is significantly improved compared with the traditional expansion method, which is suitable for expanding crack images.

Gain-switched semiconductor lasers tend to produce optical pulses that are wide in width and have a pulse base of a certain size. In order to obtain pulse quality of gain-switched semiconductor lasers, a three-stage pulse shaping scheme was proposed. First, the optical pulse width at the output of the gain-switched semiconductor laser was compressed from 39.381 to 26.681ps using a dispersion-compensated fiber. Then, the width of the optical pulse was further compressed by using an erbium-doped fiber amplifier and the high-order soliton effect of a dispersion shifted fiber to 20.916ps. Finally, the self-phase modulation effect of the semiconductor optical amplifier was used to distinguish the spectrum of the pulse pedestal from the pulse center, and the optical filter was used to filter out the part of the spectrum corresponding to the pulse pedestal, thus eliminating the pulse pedestal and compressing the pulse width to 18.497ps. The experimental results show that this three-stage pulse shaping scheme can effectively compress the pulse width and reduce the pulse pedestal, thus improving the quality of the output optical pulse of the gain-switched semiconductor laser.

Aiming at the problem of lacking reliability evaluation and robustness guarantee in existing single-person pose estimation networks′ results, a testing-time-augmentation (TTA) algorithm based on aleatoric uncertainty was proposed. In this TTA algorithm, diverse outputs were firstly obtained by stochastic parallel data augmentation and model inference. Then, the reliability evaluations of those outputs are acquired by calculating their aleatoric uncertainty. Finally, those outputs and their uncertainty were fused according to the reliabilities to obtain a more accurate and robust result as well as its evaluation. Experiments on the MPII dataset show that this algorithm can be applied to any existing single-person pose estimation network in a plug-and-play manner, leading to a more precise and robust result with its uncertainty evaluation.

The conventional frequency conversion of satellite payloads in electronic domain has the drawbacks such as susceptible to electromagnetic interference, limited spur-free dynamic range (SFDR), as well as narrow band. The introduction of microwave photonic into satellite communication system has shown many interesting advantages, overcoming the limitations of signal frequency conversion in electric domain and improving the performance of the on-board frequency channel. A broadband microwave photonic frequency conversion technology based on parallel Mach-Zehnder modulator (MZM) and balanced coherent heterodyne detection is proposed in this paper. Better common mode noise suppression and reduced harmonic distortions were achieved by using balanced coherent heterodyne detection. While combining the advantages brought about by the suppression of carrier modulation, the SFDR of the frequency conversion system were significantly improved. A spur suppression ratio better than 60dB and a SFDR better than 100dB·Hz2/3 in microwave photonic frequency conversion system is proposed and experimentally demonstrated. Essential theoretical basis and technical support are provided for the new scheme of microwave photonic frequency conversion of satellite payloads.

In order to improve the resource allocation ability of optical networks for massive and differentiated power services and reduce the algorithm training time of large-scale services, a smart grid optical network resource allocation scheme based on the multi-agent deep deterministic policy gradient (MADDPG) algorithm was proposed. The large-scale and differentiated power services were considered, the optical core network slice model of smart grid was built and the optimization problem aiming at maximizing the income of power grid companies was proposed. Conditional judgment mapping was proposed to simplify the optimization problem. At the same time, the improved MADDPG algorithm was designed to reduce the training time and meet the real-time needs of the network by placing different services to different agents. Lastly, simulation results show that the proposed algorithm has better reward, lower cost and time delay, and lesser training time.

In order to improve the accuracy of star centroid extraction of star sensor under single event effect condition, an on-orbit correction method based on PSF reference model was proposed. With the construction of star reference model and residual image correction, the proposed method could effectively accomplish single event effect noise elimination and star shape correction, which reduced star centroid error. Compared with existing methods, the proposed method could maintain the energy of stars while denoising. A simulation experiment certificated the effectiveness of the proposed method. A contrast experiment showed the superiority of the proposed method compared with other denoising algorithms.

Aiming at the limitation that the existing inertial detection system based on single-axis fiber optic gyroscope cannot be used for deformation of horizontally curved bridge structure, a single-axis fiber optic gyroscope-based detection method for track deformation of curved bridges was proposed. Firstly, the principle of linear bridge deformation measuring based on single-axis fiber optic gyroscope was presented, and the error source of gyro and the difficulty of curved bridge detection were explained. Then the feasibility of curved track measuring by single-axis fiber optic gyroscope was analyzed according to the navigation algorithm. Secondly, a curved test track, a set of track detection trolley and wireless linear acquisition system were built. Finally, the integrated linear detection system on the test track was tested, different test stages by changing the deformation degree of the test track were performed, and then the actual measurement results were compared with the micrometer measurement results to verify the feasibility and accuracy of the proposed algorithm. The results show that the method can identify the precise deformation of curved track under different test stages with an accuracy of less than 1mm. Owing to the simple measuring principle, when the systematic implementation and low measuring cost combined with the equipment of bridge track detection, the proposed method will provide a new approach for the massive deformation measurement of various large-scale bridges without closing bridge or stopping bridge transportation.

In the underwater target detection of LiDAR, the underwater transmission of laser is seriously attenuated due to the absorption and scattering of laser by suspended particles in turbid water, especially the noise caused by backscattering will reduce the target contrast and even drown the target echo signal. The carrier modulation technology can effectively suppress backscattering and increase the signal-to-noise ratio of target echo signal. In this paper, the Boolean chaotic signal was used as the carrier modulation signal. Based on its inherent high-frequency intensity modulation characteristics, an underwater imaging system of Boolean chaotic modulation LiDAR was constructed. The three-dimensional imaging experiments of target objects in turbid water with different attenuation coefficients were carried out in the laboratory water tank environment, and the three-dimensional imaging effects of the target in different water quality were compared.

With broadband femtosecond (FS) oscillator as the excitation light source, a two-photon fluorescence (TPF) microscopy imaging system was built. Under the broadband excitation of FS pulses, TPF spectrum of Rhodamine B solution was measured and TPF microscopy imaging study of solid Rhodamine B samples was performed. In the study of TPF microscopy, the relationship between TPF intensity and excitation pulses power was analyzed. Besides, the trend of the two-photon fluorescence intensity with the polarization direction of the excitation pulse was studied through changing the polarization direction of the linearly polarized excitation light field by using a half-wave plate, and the sinusoidal-like modulation of the two-photon fluorescence intensity was realized.