Micro-electro-mechanical (MEMS) resonator gyroscope is a kind of solid wave gyroscope, which is often fabricated by micro-nano fabrication technology, and has features of small size, low power consumption, low cost, and suitable for batch fabrication. Since the birth of the first hemispherical resonator gyroscope in the world in 1975, the structure topology of the MEMS resonator gyroscope has undergone a transformation from three-dimensional structure to two-dimensional structure. In this paper, the development of MEMS resonator gyroscope was summarized in the line of the development of topology. Finally, the current problems were analyzed and future development was prospected.

The research on graphene/silicon-based hetero-integrated photonic devices has made great progress in recent years. The graphene/silicon-based heterogeneous integrated devices have shown excellent performance such as ultra-large bandwidth and ultra-low power consumption thanks to the unique physical properties of graphene, such as ultra-high carrier mobility and ultra-high nonlinear coefficient. In this work, we reviewed the typical graphene/silicon-based heterogeneous integrated devices reported in recent years, including graphene/silicon-based electro-optical modulators, graphene/silicon-based thermo-optical modulators and graphene/silicon-based photodetectors, briefly described their principles and properties, and made a prospect for their future applications and development.

Thin film LiNbO3 modulator has become a hot spot in the industry in recent years because of its small size, high bandwidth, low half wave voltage and other advantages. In this paper, the research progress on waveguide structure, electrode structure and bias point control technology of LiNbO3 modulator were reviewed. The performance of three different waveguide structures, including planar buried waveguide, ridge waveguide and photonic crystal waveguide, were analyzed. The characteristics and design considerations of the lumped and traveling wave electrode structures of LiNbO3 modulator were discussed. The advantages and disadvantages of the power method and the pilot method in the bias point control of electro-optic modulator were compared, as well as the related research results. Based on this, the key technologies and future research directions for realizing the LiNbO3 modulator with smaller volume and higher bandwidth were further analyzed.

MOEMS gas sensing technology is an innovative technological solution for optical gas sensing techniques combined with MOEMS technology and new materials. MOEMS gas sensor has many advantages such as lower cost, higher integration, stronger anti-interference, higher test accuracy and so on. Firstly, the structure and working principle of primary optical gas sensing systems were introduced. Subsequently, the latest achievements, microoptical devices and microoptical system in MOEMS gas sensing technology were introduced. Taking the current research status of the MOEMS gas sensing devices as clue, challenges and priorities of MOEMS gas sensor were discussed.

In this paper, a novel wave-like disk resonator gyroscope (WDRG) with high mechanical sensitivity and low zero-bias stability was proposed and developed. The structure was designed by turning the traditional disk resonator gyroscope (DRG) rings into wavy rings, which had the potential to provide a higher thermo-elastic quality factor. In addition, the WDRG had higher fabrication error immunity compared with the traditional DRG. The performance of WDRG was further improved by optimizing the structural parameters. The influence of the main structural parameters on the WDRG′s critical performances was given through finite element method (FEM). The new prototype′s optimized thermalelastic quality factor, mechanical sensitivity, and bias stability are 450k, 1.05μm/(°/s), and 0.076°/h, respectively. Compared with traditional DRG, the zero-bias stability is significantly decreased by 90%, and the thermalelastic quality factor and mechanical sensitivity are considerably improved by 215% and 950%, respectively.

Taking the cantilever structure of capacitive MEMS accelerometer as the research object, the typical failure mode and failure mechanism of MEMS accelerometer in vibration environment were analyzed. Based on Miner′s theory, the stress-life curve was introduced to establish the fatigue reliability model. The reliability model of plastic deformation was established based on stress intensity interference theory considering strength degradation. The Monte Carlo method was used to verify the accuracy of the two reliability models, and the influence of the key parameters of the model on the reliability was analyzed. The results show that the vibration stress level and the yield strength of the material had significant influence on the reliability. Reducing the stress amplitude and increasing the yield strength can improve the reliability of the MEMS accelerometer.

Thermoelastic damping is a basic energy dissipation mechanism in the resonator, which determines the performance limit of high Q resonator. Testing the mass suspension support beam is difficult to solve analytically due to the variation of the cross section. Studies have shown that the classical L-R theory can be applied to the structure after the mass rigidity assumptions, yet the assumptions with respect to calculation error caused by the actual device is inconclusive. To solve this problem, a comparative analysis between the L-R calculation and ANSYS finite element analysis method was used to compare the first-order intrinsic frequency and the calculated error of thermoelastic damping coefficients at this frequency when the scales of the support beam and mass block were varied respectively. The results show that the calculation error of L-R theory is too large to calculate thermoelastic damping coefficient of mass suspension beam structure accurately, but it can estimate the change trend of thermoelastic damping effectively when the scale changes.

To solve the problem of the substrate′s slow thermal conduction for flexible temperature sensors to quickly monitor the temperature of bearings and other curved surfaces, high thermal conductivity composites were prepared by doping 3wt% graphite (GR) into polyimide (PI), which reached a thermal conductivity of 0.777W·m-1·K-1 and had good insulation properties. Based on the microfabrication technique, Pt film flexible temperature sensor was prepared on the GR/PI composite film, and its dynamic response characteristics are improved with the response time of 71ms, which is better than that of the Pt film flexible temperature sensor on pure PI substrate. In addition, the electrical properties such as linearity, sensitivity and measurement repeatability are good. The prepared sensor was used for temperature measurement on metal shaft surfaces, and the difference between the measured values is small (within ±2℃) compared with a commercial infrared camera.

A capacitive artificial hair sensor that enables two-dimensional wind velocity measurement was designed. The sensor detected flow velocity by differential capacitance, and the handle layer of wafer corresponding to the sensor motion structure was completely etched. The relationship between the differential capacitance of the sensor and the wind velocity was analyzed and obtained by multi-physics field simulation of fluid-solid-electrostatics field using finite element analysis software. With the theoretical accuracy of the capacitance sensor AD7746, the wind velocity sensitivity of the sensor is calculated to be 0.25mm/s. In addition, a process flow for the microfabrication of the sensor based on SOI wafer was designed.

The damping characteristics of eddy-current damping of a diamagnetically stabilized levitation structure were studied. A mathematical model for solving eddy-current damping and damping coefficient was established. With the help of MATLAB and COMSOL 5.6, the characteristics of eddy-current damping and the influence of external excitation frequency, amplitude, thickness of floating magnet and thickness of conductor plate on eddy-current damping were studied by three-dimensional electromagnetic field finite element simulation analysis method. The results show that the eddy-current damping can be increased by increasing the radius and thickness of the magnet, increasing the side length and thickness of the magnet and reducing the levitation gap. In addition, increasing the amplitude and frequency of the external excitation can also increase the eddy-current damping, but the eddy-current damping will show phase lag when the excitation frequency is increased. The results have certain reference significance for analyzing the vibration characteristics of the anti-magnetic levitation structure.

Aiming at the problem that vehicle vibration affects the heading accuracy of MEMS IMU, a method that can effectively suppress vibration noise and improve heading accuracy and stability is proposed. Firstly, the minimum mean method was used to preprocess the data to improve the signal-to-noise ratio. Then, the bias noise of gyroscope was filtered by using the complementary characteristics of accelerometer and gyroscope. Finally, the extended Kalman filter was used for further filtering. A total of 4 hours of field experiment results show that IMU is less affected by carrier vibration, and the accuracy and stability of heading are improved. The relative heading error after large-angle mechanical motion is 3.08° and the heading variance at rest is 2.44×10-5.

The electromagnetic actuator has a wide application prospect in communication, automatic testing, and power electronics due to its high output force, long stroke, and no contact, but it is difficult to meet the development demand of miniaturization and integration of electronic systems in related fields due to its large size and complicated manufacturing process. To address the above problems, a prototype of miniaturized electromagnetic actuator was designed and manufactured by applying planar integrated coils and high aspect ratio microstructure. Preliminary test results show that the output force of the device can reach the mN level, the output displacement is greater than 50μm, and the response time is less than 10ms, which indicates a feasible technical path for further research on the device.

Free space optical communication (FSOC) based on orbital angular momentum (OAM) has the advantages of large communication capacity and fast information transmission. The FSOC system uses the atmosphere as the transmission medium, which will be affected by atmospheric absorption and scattering. As a result, the transmission quality of the OAM beam is seriously degraded. Based on the theory of OAM multiplexing technology and atmospheric turbulence model, this paper analyzed the influence of different turbulence intensities on the bit error rate and channel capacity of OAM beam transmission, and analyzed the research status of the mitigation effect on atmospheric turbulence by introducing multiple-input multiple-output equalization technology and adaptive optics technology respectively into FSOC system. The inhibition effects of different algorithms in the two technologies were compared and analyzed, and the technology development status was summarized and prospected.

For the application of low noise and high linearity in microwave photonic link, the influence of waveguide cross coupling effect of M-Z electro-optic modulator on harmonic suppression ratio was studied. Firstly, through the joint simulation of OptiBPM and MATLAB, it was found that the cross coupling effect between waveguides led to a shift of the modulator RF electrode and bias electrode operating point, and then reduced the harmonic suppression ratio. Secondly, the phenomenon was verified by a special lithium niobate modulator. At last, a method to detect the cross coupling effect of M-Z electro-optic modulator was proposed. This discovery not only breaks the blind area of the influence of waveguide structure on harmonic suppression ratio, but also provides a certain reference for the development of ridge waveguide and photonic crystal thin film lithium niobate modulator for microwave photonic technology.

In order to meet the needs of high bandwidth and circularly polarized communication in future wireless communication, a circularly polarized terahertz antenna based on a Fabry-Perot cavity is proposed. The antenna adopted a quasi-optical waveguide feeding mode, the circular waveguide was cut at 45° to realize the linear-circular polarization conversion of the antenna, and the partial reflecting surface of the dielectric material was used to improve the gain of the antenna. The simulation analysis shows that the maximum gain of the antenna is 14.4dBic at 228GHz, the impedance bandwidth (S11＜-10dB) is 40GHz, the 3dB gain bandwidth and the axial ratio bandwidth are 18 and 27GHz respectively, and the overlapping bandwidth of the three is 18GHz. The antenna has the advantages of good directivity, high bandwidth and circular polarization in the entire working frequency band, and has high reference and practicability in terahertz/millimeter wave wireless communication.

Aiming at the problem that achieving high frame rate for traditional column-level analog-to-digital converter (ADC) in the image sensor is difficult, a hybrid high-speed column-level ADC consisting of a successive approximation register (SAR) ADC and a single slope (SS) ADC was proposed, which reduced the conversion period by about 97% compared with the traditional SS ADC. Achieving correlated double sampling (CDS) of the pixel by the capacitance of the SAR ADC, and making a difference in the analog domain, the quantization time of CDS was shortened to one conversion period, which further improved the quantization speed of ADC. In order to ensure the linearity of column-level ADC, a 1bit redundancy algorithm was proposed, which could achieve differential nonlinearity of +0.13/-0.12 LSB and integral nonlinearity of +0.18/-0.93 LSB . Simulation results based on 180nm CMOS process show that the column-level ADC has a conversion period of only 1μs, a spurious-free dynamic range of 73.50dB, a signal-to-noise distortion ratio of 66.65dB, and an effective number of bits of 10.78bit at a clock of 50MHz.

In this study, three-dimensional vertical graphene was prepared on copper foil using radio frequency plasma enhanced chemical vapor deposition technology with methane as carbon source. By adjusting the growth parameters, seven groups of comparative experiments were carried out. The morphology, mass and layer number of vertical graphene were characterized by scanning electron microscope and Raman spectroscopy. The field emission characteristics of vertical graphene were measured by a secondary structure field emission instrument. The relationship between the field emission characteristics of vertical graphene and its morphology, mass and density was studied. The open electric field intensity of the field emission characteristic as low as 0.29V/μm was obtained. The results show that vertical graphene is a material very suitable for field emission application and has broad application prospects in vacuum electron sources in the future.

In order to further realize the basic requirements of high gain and high bandwidth of laser echo pulse processing circuit, the structural design of CMOS integrated circuit was deeply studied in this paper. The improved RGC transimpedance amplifier, the cascade structure of automatic gain control Cherry-Hooper, and the two terminal output source follower were used as preamplifier, voltage broadband amplifier and buffer link respectively to form the receiving path of laser pulse signal. The circuit bandwidth expansion was realized by using MOS_L equivalent parallel inductance peaking technology. The circuit performance parameters were simulated and tested under the CMOS process condition of 0.5μm. The results show that the signal bandwidth, DC gain, input impedance and output voltage response amplitude of the signal processing circuit are 100MHz, 141dB, 117Ω and 1V respectively. Finally, the specific layout design and test scheme of the circuit were proposed.

In order to extend the detection range of position sensitive detector, and solve the problem that the light spot cannot be accurately positioned when the light spot is off-target on the PSD photosensitive surface, a light spot off-target error compensation method is proposed. The variation law of the spot energy center of PSD detection before and after the off-target was analyzed, and the functional relationship between the PSD light intensity signal and the position detection error was established. The experimental results show that: when the size of the PSD photosensitive surface is 12mm×12mm, for a Gaussian light spot with a radius of 5mm, the X-axis detection range of the PSD photosensitive surface is increased by 66.7% after compensation by the spot compensation method proposed in this paper, and the average relative error of position detection is no more than 5%. This method is important to improve the performance of PSD position detection.

The roughness-induced scattering loss (LossR) of photolithography-fabricated polymer optical waveguide was investigated theoretically and experimentally. The effects of the LossR including roughness, waveguide dimension, and operation wavelength on the LossR were studied. The roughness of the waveguide′s sidewall and top/bottom surface was measured by employing a laser confocal microscope. The results show that the average roughness of sidewall is about 60nm, which is 3 times of that of top/bottom surface. As a result, the LossR of sidewall is dominant and is 9 times of that of top/bottom surface. Based on the above theory and experimental results, low-loss single mode polymer waveguides operating at the wavelength of 1310nm with average loss of 0.35dB/cm were designed and fabricated, which have broad application prospect as the key transmission media of the high-speed high-density optical backplane.

In order to obtain the dielectric assembly characteristics of nanowires in the conductive island microelectrode system, a comparative experiments of nanowire manipulation in both systems were conducted based on the planar microelectrode pairs and the conductive island microelectrode systems. The nanowire dielectric assembly models of the planar microelectrode pairs and the conductive island microelectrode systems were established respectively: The motion trajectory of the nanowires from the initial position to the final bridging onto the microgap under the two models was explored. And the nanowires subjected to dielectrophoretic forces, alternating current heat flow, and the electrokinetic behavior of cooperation between the two in a conductive island microelectrode system were analyzed. The conductive island microelectrode system has a strong dielectric capture effect on nanowires, and the addition of conductive islands can make better capture of nanowires to the microgap. Meanwhile, the dielectric assembly of nanowires is affected by frequency. When the frequency reaches the flip frequency, the microfluidic vortex generated above the microgap can transport nanowires in the far-field region to the assembly area, which makes the nanowires to be assembled to the microgap by the positive dielectrophoretic force.

Traditional ground object spectrometers have high requirements for optical signal intensity and can only be used during the day but cannot be used at night, which leads to high uncertainty of on-orbit radiometric calibration of remote sensing at night. A technical solution is proposed to enhance the information acquisition capability of the spectrometer under low illumination conditions by directly coupling the traditional spectrometer′s CCD (Charge-Coupled Device) detector with the image intensifier. Based on this technology scheme, the spectrometer could effectively measure ground targets′ spectral information at night. The experimental results show that the low-level light spectrometer can effectively measure the spectral information of the ground target with good and stable performance under the condition of moonlight and starlight. And the spectrometer can be applied to night remote sensing calibration, night target spectral information acquisition, and other application fields, laying a technical foundation for improving the accuracy of night remote sensing calibration in orbit.

Aiming at the application requirements of laser communication and atmospheric short-wave infrared (SWIR) spectroscopy of low-orbit satellites, a design method for star short-wave infrared imagers is proposed. Since the anti-total dose radiation capacity of the low-orbit satellite system is required to be more than 20kRad (Si), the method first screened the InGaAs focal plane detector with a total dose radiation resistance of more than 20kRad (Si). Then the aerospace-level components were used to design the corresponding timing drive, temperature control, analog-to-digital conversion, image transmission, remote control telemetry and other hardware circuit modules to form the hardware part of the imager. Finally, the PID temperature control algorithm was applied to achieve accurate temperature control of the imager, and the non-uniformity correction algorithm and image enhancement algorithm were used to improve the image quality of the imager. After test verification, the short-wave infrared imager has a total dose radiation resistance capacity of 25kRad(Si), a dynamic range greater than or equal to 61dB, and a non-uniformity less than or equal to 1.9%, which meets the requirements of short-wave infrared spectroscopy detection of low-orbit satellites.

Aiming at the wavelength drift problem caused by the influence of ambient temperature on fiber Bragg grating (FBG) strain sensor, the online prediction algorithm that combined particle swarm optimization (PSO) with sliding window extreme learning machine (SWELM) is proposed for temperature compensation. The PSO algorithm was used to optimize the sliding window and the number of neurons in the hidden layer of the SWELM network, which improved the prediction accuracy of the model, and the minimum root mean square error of the model prediction could reach 0.06pm. PSO-SWELM realized online update and wavelength drift prediction of strain sensor data, and differential calculation of real-time measurement data and prediction data completed temperature compensation. PSO-SWELM was compared with SWELM, and the results show that the accuracy of the proposed algorithm is improved by an average of 11.04%, and has good temperature compensation effect.

Aiming at the problem of grayscale difference in multispectral images of aerial filter array, a new method of the strip grayscale correction algorithm is proposed in this paper. Firstly, the strip image template was constructed for multispectral image, and the scale invariant feature transform algorithm was used to extract image feature points and calculate inter-image coordinate transformation matrix, which was used to determine the overlap region of strip image. Secondly, the mean value of the greyscale of pixels in the overlapping area of each strip image was calculated, and the greyscale correction coefficients between adjacent images were fitted with the greyscale of each strip of greyscale intermediate image as a reference. Finally, the projected image templates were used to extract sequential single-band strip in turn and stitch them together to obtain a single-band image with same greyscale. Experimental results show that this method can effectively solve the difference in the greyscale of multispectral image strips of aerial filter array, and can maintain the maximum spectral information characteristicsof the ground feature.

In view of the problems that the miter gate of ship lock is in the complex water environment of low-speed, heavy-duty and overload operation for a long time, and the existing detection methods are low in automation, time-consuming and labor-consuming, and vulnerable to electromagnetic interference, a miter gate structural health monitoring system based on fiber Bragg grating sensing technology is proposed. Firstly, the sensing principle of fiber Bragg grating was described. Then, based on this principle, the structural health monitoring system of miter gate was constructed. The system could sense the strain changes of miter gate during operation, and realize the functions of real-time data display, abnormal data monitoring and early warning, historical data playback and so on. Finally, the data collected by the sensor was processed by median filter to improve the signal-to-noise ratio of the signal. The data are analyzed and compared to verify the repeatability and navigation relevance of the sensor data, which provides data support for the safe and stable work of the miter gate of the ship lock.

A simulation model of underwater Gaussian beam transmission by Monte Carlo method was established, and the influence of receiver tilt angle and receiver position on the attenuation of received optical power based on this model was emphatically studied. The simulation results show that in the underwater channel, the received optical power reaches the maximum when the receiver array is correctly aligned the laser beam, and the received optical power gradually decreases with the increase of the receiver tilt angle. When the receiver moves forward along the Y-axis, the received optical power remains unchanged when the receiver is within the diameter of the laser beam. When the receiver is outside the diameter range of the laser beam, the received optical power decreases with the increase of the distance from the origin of the receiver. The simulation results can provide reference for the practice of underwater laser communication engineering.

Distributed optical fiber composite overhead ground wire (OPGW) health monitoring based on FBG (fiber Bragg grating) sensor has been widely studied. In this paper, a wave prediction method based on cubic spline function fitting is proposed for OPGW galloping cable event. Firstly, the mathematical relation between the phase variation of sensor and the galloping cable wavelength was established through theoretical derivation. Then, the simulation results of the phase shift signal before and after the cubic spline function fitting under ideal galloping condition were analyzed, and the effectiveness of the proposed method was proved. Finally, it was applied to a 220kV line, and the intensity graphs of galloping monitoring in typical weak wind environment and strong wind environment were compared and analyzed. According to the actual monitoring results, the method selected in this paper can effectively improve the signal characteristics of intensity graphs, and it can be concluded that the wavelength within the range is about 200m under strong wind condition, and the wavelength within the range is about 50m under weak wind condition. This method provides technical reference for intelligent monitoring of image recognition of cable galloping events and has strong application prospect.