In the field of optical fiber communication，the asynchronism of carrier frequency will cause the data transmission to the terminal cannot be demodulated. To achieve the stable transmission of carrier frequency signal on optical fiber，an adaptive phase compensation system is designed in this paper. The system combines analog circuit and digital signal processing technology，uses signal frequency division，mixing and other means to change the two-way phase jitter introduced in the process of signal round-trip transmission into single-way phase jitter，and uses a single analog phase shift for pre-compensation. By introducing PID control algorithm，the phase shift voltage is regulated accurately，and the accuracy and stability of the system compensation are improved. The influence of ambient temperature on the link delay is analyzed，and the phase drift of the remote signal after compensation is compared with that in the free transmission state. The results show that the link delay jitter is stable within 15 ps，and the long-term stability of the remote signal reaches 6.9× 10-19/104 s. The performance of the adaptive phase compensation system at different distances is compared with the same temperature change model. The results show that the scheme can reach steady state within 30 s of warming up and realize effective compensation. The system supports the technology of long distance optical fiber frequency transmission.

Infrared small target detection is usually limited by a long imaging distance，which makes it difficult to extract target features. How to enhance target feature expression is one of the main research directions in recent years. However，too complex feature representation will lose the speed of inference. In this paper，we use reparameterization technology and residual network as feature enhancement module and feature fusion module，and achieve good results on the datasets. On SIRST and IRSTD-1K datasets，the proposed method achieves 0.734 and 0.638 mIoU，while having only 0.306M and 1.114G FLOPs in parameter number and computational complexity. Our model can maintain fewer parameters in the inference stage while having performance similar to or even leading other leading methods，which has obvious advantages in a serial environment.

Gray coding method is widely used in 3D reconstruction of structured light projection because of its robustness and noise resistance. In order to apply gray code method to real-time measurement，multi-level Gray code is used to reduce the number of projection amplitude and improve the measurement efficiency. However，in the process of three-dimensional measurement with color objects，because of the difference in reflectance of different color，the fringe order in 3D reconstruction may be confused，and the error caused by chroma is obviosly increased by multiple gray levels. In order to adapt to real-time measurement for color objects and improve the characteristic of anti-color interference，a multi-level Gray code demodulation method using HSI color space is proposed. Intensity in HSI color space instead of the gray in RGB space is used in multi-level Gray code decoding and fringe order extraction，at the same time，the color texture of the object surface can also be reconstructed without capturing additional auxiliary color texture patterns. Experimental results show that this method can effectively correct the order entanglement caused by color object chroma，and reduce errors in fringe order. It may play a prospective application in real-time 3D measurement for color texture object.

To investigate the influence of laser power and scanning path spacing on the height of microstructures formed by the scanning laser shock forming process，this paper employs nanosecond fiber laser to form micro protrusions array with diameter of 200 μm on aluminum foil with thickness of 20 μm by Laser shock forming. The three-dimensional morphology of micro protrusionsis measured by using a laser confocal microscope. The results indicate that during the process of laser power changing from 10 W to 18 W，the height of the formed microstructure increases from 17 μm first to 29 μm and then decreases to 12 μm. When the scanning line spacing changes from 30 μm to 50 μm，the height of the formed microstructure increases gradually from 14 μm to 30 μm. The influence of laser power and scanning line spacing in the scanning laser shock forming process is essentially the common result of the constraint of the energy absorption layerthickness and the influence of the strength of the shock wave generated by laser ablation of the energy absorption layer. This comprehensive influence needs to be paid attention to in the multi pass scanning laser shock forming.

In non-telecentric structured light projection measurement system，the frequency mismatch problem between the designed virtual grating and the captured carrier frequency fringe for single-shot spatial phase detection（SPD）will degrade the measurement accuracy and the range of the method. We propose a new demodulation frequency acquisition method by calculating the frequency value at the local peak points to fit the frequency function to obtain the virtual grating that can match the carrier frequency of the deformed fringe well. In addition，the piecewise Hilbert transform is proposed to eliminate the fringe background to be ease to spatial filtering. The improvements not only nearly expand two times measurement range but bring higher measurement accuracy of single-shot SPD method because more detail of the tested object can be obtained. Simulation and experimental results demonstrate the effectiveness of the proposed method. The results show that the maximum error of the single-shot SPD method is reduced by almost half after removing the fringe background. This method provides a reference for spatial fast 3D detection based on structured light projection.

The tilt monitoring for OPGW（fiber optic composite overhead ground wire）transmission tower under harsh environment has important engineering significance. In this paper，based on ultra-weak reflected FBG （fiber Bragg grating），combined with wavelength-division/air-division multiplexing，we propose a inclinometer array monitoring technology for OPGW tower. Firstly，the mathematical relation of FBG wavelength，strain and tower angle is deduced theoretically. Then，based on COMSOL finite element simulation，the stress variation of the tower under the condition of wind excitation and uneven tension is analyzed. Finally，the basic parameters of the inclinometer are calibrated by comparison test，and the sensor is applied to a 220 kV transmission tower in eastern inner mongolia province for tilt monitoring，and the preliminary results of tilt monitoring are obtained. The actual monitoring results show that the proposed method can effectively monitor the tower inclination，the strain sensitivity coefficient of the ultra-weak reflected FBG is about 1.2 pm/με，the sensitivity coefficient of the inclination sensor is 51.8 pm/°，and the monitoring results of the tower inclination is about 2.64° under normal circumstances. This method provides a technical reference for multi-parameter health monitoring of OPGW transmission lines and has a strong engineering application prospect.

In recent years，endoscopes have been widely used for the detection of internal defects in pipelines in various environments. This article focuses on the high-precision defect detection requirements of different calibers of gun barrels，a wide-angle endoscope lens with a large field of view and short focal length is designed. This lens achieves panoramic imaging of the internal walls of gun barrels within the caliber range of Φ76 mm to Φ155 mm，determines the position of internal defects，and allows the entire lens to rotate for side-view imaging of different areas of the inner walls，enabling high-precision measurement of defects. The system is designed using the Zemax design software based on the concept of a retro focal lens. Non-spherical surfaces are utilized to improve the imaging quality of the system. The final optical system achieves a field of view of 120°，a focal length of 2.5 mm，a total length of less than 30 mm，a maximum distortion value of less than 15%，and a full field of view greater than 0.3 at a detector cutoff frequency of 84lp/mm. The optical system has a simple structure，a wide applicable caliber range，and good imaging quality，meeting the requirements for gun barrel defect detection.

The detection of defects in ground wires is often slowed down and less accurate due to the large size of UAV aerial images and complex background environment. To address this issue，this paper proposes a lightweight ground wire defect detection method based on LSD and deep learning. First，the LSD algorithm is used to extract linear features from the images. Then，a segmentation baseline is fit by combining it with RANSAC. Based on the segmentation baseline，the region of the ground wire is now clearly segmented，background interferences are eliminated，and image size sent to the detection network reduced. After modifying the YOLOv5 backbone network，the number of parameters is reduced，making it easier to deploy on edge computing equipment. The proposed method reduces the inspected area and suppresses interference. It improves the accuracy from the original 67.9% to 71.3%，at the same time，the detection speed is increased by 12%. It has the advantages of high precision and fast speed，which is suitable for deployment on edge computing equipment.

State monitoring of the processing process is a prerequisite and foundation for achieving intelligent monitoring of the processing state. To address the issues of various fault features during the processing process，incomplete information collected by a single sensor，and low reliability of the obtained diagnostic results，a multi-sensor intelligent monitoring system for the processing process was developed based on the LabVIEW platform. This system can collect，store，analyze， and diagnose current，vibration，noise，and acoustic emission signals during the processing process. Experimental results show that the system can accurately collect signals from multiple sensors，as well as store，analyze，and diagnose the signals，improving processing efficiency and product quality. This system can reduce losses and waste in the production process，and can achieve more intelligent and efficient monitoring of the processing state in practical production.

In order to meet the demand of gun sight in military products，a set of gun sight which can realize 8× ~32× continuous magnification is designed. The design idea and method of the gun scopes are described in detail. Firstly， according to the design index，the objective lens group，eyepiece group and relay mirror group are decomposed and calculated. Then，the Gauss optical design of the objective lens，the eyepiece and the whole gun aiming system is carried out to determine the complexity of the whole system and the optical structure parameters. Then，according to the results of Gauss structure design，the initial structure is selected，and the optimization operand is selected according to the design index to optimize the system. Finally，the evaluation of the overall system design and optimization results is completed. In the final design results，the objective lens of the gun sight has an aperture of 56 mm，the eyepiece has an aperture of 50 mm，and the total length of the system is 410 mm；the aberration of the low magnification group is 2.4%，the on-axis diffuse spot radius of the high magnification group is 6.2 μm，the off-axis diffuse spot radius is 8.3 μm，and the aberration index meets the design requirements.

In order to solve the limitations of existing optical systems in airborne and other fields，optical free-form surfaces with rich degrees of freedom are introduced to design a small F number，large field of view，and lighter airborne mid-wave infrared off-axis two-mirror optical system. The reflective optical system is adopted to eliminate light occlusion by off-axis，and the free-form surface expressed by XY polynomials effectively balances the advanced aberrations by using the first 6 terms. Finally，a medium-wave infrared optical system with a focal length of 240 mm，a field of view angle of 3.8° and an F number of 3 is obtained，and the system's Modulation Transfer Function（MTF）is close to the diffraction limit in the full field of view，and the radius of the Root Mean Square（RMS）of each field of view is within 15 μm of the cell size of a single detector，and the overall physical size is less than 190 mm（X）×190 mm（Y）×240 mm（Z）. The final results show that the system not only meets the imaging quality，but also has simple structure and good lightness，and can be widely used in airborne ground reconnaissance imaging and other fields.

Electrowetting liquid lens is a type of lens that can change its own optical power by changing the applied voltage at both ends，without changing the optical spacing. Therefore，the zoom optical system designed based on liquid lenses can greatly reduce the complexity of traditional mechanical zoom optical systems. This article is based on the Corning A39 liquid lens and uses ZEMAX simulation to design a small binary single liquid lens zoom optical system with a focal length variation of 16~32 mm，field of view angle variation of 32°~16.36°，zoom ratio of 2，short focal F-number of 6.3，long focal F-number of 12.8，and a maximum aperture of 10mm within a 20 D range of optical power variation.

The warm atomic optical clock is an important development direction of miniaturized optical clock. As the core of the warm atomic optical clock，the non-magnetic temperature control is one of the key technologies of the warm atomic optical clock. The temperature fluctuation and magnetic field noise introduced by heating will affect the stability of the warm atomic optical clock. In view of the high-precision non-magnetic temperature control requirements of the warm atomic optical clock with cesium double photon transition，a double layer non-magnetic temperature control system is designed in this paper. The four-wire system is used to collect temperature information，and the PID is simulated to realize feedback temperature control. The heating components are designed with double snake heating film to reduce the magnetic field disturbance caused by heating current. Experimental results show that the non-magnetic temperature control system has a four-hour temperature stability of 0.004 ℃ when the working temperature of the atomic gas chamber is 80 ℃，and the magnetic field noise is less than 100 nT，which meets the design requirements of the warm atomic optical clock and ensures the smooth progress of the warm atomic optical clock experiment.

In order to solve the problem of low processing efficiency due to the over-reliance on manual experience in traditional planar mono-pendulum polishing，the material removal function of workpiece feature points at different relative positions of workpiece and grinding disc is established based on the Preston's principle，and the influence law of workpiece velocity field distribution on planar surface shape is studied. The surface shape of the workpiece is rasterised. The velocity field distribution of the workpiece and the velocity field distribution of the grinding disc are modelled，and the relationship between the velocity field changes at the workpiece's characteristic points and the amount of material removed is simulated using matlab when the workpiece oscillates relative to the grinding disc. A single-factor experimental validation method was used，with a fixed workpiece pendulum amplitude of 0.35 rad，a pendulum speed of 0.09 rad/s and a range of pendulum angles of［0.49 rad，2.79 rad］，for simulation validation. The results show that the greater the difference in the velocity field of the oscillation path of each feature point of the workpiece，the higher the surface accuracy of the workpiece，which provides a new idea and method to find the optimal processing parameters quickly and improve the efficiency of plane processing effectively.