Nitrogen vacancy (NV) color center is a diamond luminous defect with good optical properties and spin characteristics. In recent years, NV color center has attracted the attention of many researchers due to its great application prospects in the fields of super-resolution imaging technology, quantum measurement and quantum information. At present, high-quality NV color centers with controllable concentration and spatial position can be prepared through various means, which promotes its application in the fields of quantum sensing and quantum information. The electron spin Hamiltonian of NV color center is related to many physical quantities, so quantum precision measurement can be realized by reading the electron spin state of NV color center. As a solid-state spin quantum system with long electron spin coherence time and stable performance, NV color center can realize safe and efficient quantum information processing. In recent years, the sensitivity of quantum measurement has been rapidly improved with the development of NV color center preparation technology. The structure and basic characteristics of NV color center are introduced, and its preparation and application are summarized and prospected.

Mid-infrared 6.45 μm laser scalpel has potential application in high precision medicine fields, with advantage of high ablation rate and minimal collateral damage in biological tissue. The collateral damage at this wavelength amounts to several μm which is comparable to the cell size, i.e. close to the optimum value. The laser ablation mechanisms, minimally invasive surgical applications, and laser sources for 6.45 μm laser in China and foreign countries are reviewed, and the development of the research is forecasted.

The utilizing of photonic technology to generate microwave signals is a popular research topic and is widely used in communication systems, signal processing, radar and other fields. The method of using photonic technology to generate optical pulse signals with triangular time domain characteristics is imposed. And the all-optical method and electro-optical method including spectral control and time domain superposition is introduced in detail and compared. The advantages and disadvantages are analyzed in terms of pulse repetition frequency tuning capability, pulse duty cycle, pulse type and system structure stability.

The gain fiber doped with Yb3+ is the main approaches to amplify the laser at 1 μm wavelength, the laser have important application prospects in the field of high power pump source, laser radar, medical treatment and scientific research. The energy level and generation principle of the laser are introduced, and its development is reviewed. The key technologies and solutions are analyzed. Furthermore, the future developing of the laser is discussed.

Optical fibers are being studied more and more extensively in information and communication. Mode recognition technologies in optical fibers provide a concise method for fiber mode recognition. Transverse electric wave (TE) modes, transverse magnetic wave (TM) modes and mixed wave (HE, EH) modes are classified according to the scalar solutions of the fluctuation equations in step index fibers. Moreover, simulation studies are performed for representative optical fibers such as multi-clad Bragg fibers and photonic crystal fibers. And a universal mode classification method is proposed by combining the electric field line distribution of the mode and the electric field intensity distribution in the Ez direction, which helps researchers to do further investigations on optical fibers.

With advantages of great strength, hardness, thermal stability, durability and conductivity, carbon fibers are widely applied in thermal protection, shock positioning and hole-making technologies. Meantime, much research has been conducted over the application of carbon fibers in interference and energetic materials. The research achievements of carbon fibers being applied in interference materials such as infrared, radar, and smoke curtain as well as energetic materials such as propellant and explosives are introduced, which provides references for in-depth research of the application of carbon fibers and their composite materials in interference and energetic materials.

100 G SR4 optical module with the advantages of high transmission rate, mature technology and low cost has been widely used in data centers and data communication access networks. The circuit and optical path of 100 G SR4 optical module has been designed with the method of chip on board (COB) packaging technology, and the transmitting and receiving performances of the module is tested by the self-made testing system. Testing results show that the module accords with the characteristics of the agreement and can meet the requirements of 100 m short distance high-speed data communication system.

After the electromagnetic signal transmitted by the radar signal data source is collected, it is transformed from time domain to frequency domain, that is, discrete Fourier transform and adaptive amplitude beam forming, so that the signal frequency is compensated, and the waveforms of the reconstructed signal are analyzed and compared. Through the characterization of the redefined model, the visible light, infrared, radar spectrum and other band data do not lose their own information, so as to reduce the large loss of time-varying time function and selective integration in detection performance. The complete time-frequency representation of the reconstructed signal and the real signal shows that the reconstructed signal presents different time-frequency characteristics and has better energy resolution.

The sensitivity of the ring laser gyroscope based on the Sagnac principle increases with the size of the gyroscope increasing, which is directly connected to the earth and can accurately monitor the earth's rotation angular velocity. And it has wide applications such as universal time precision measurement, seismic wave detection, geodesy and basic physics. The size of the geodesic laser gyroscope is often larger for the sensitivity increasing with the size of the gyroscope increasing. However, as the size increasing, the free spectral range of the cavity becomes smaller, and it becomes difficult to obtain a single longitudinal mode. Laser gyroscope often works in the fundamental mode. Aiming at the problem of laser gyroscope mode, the experimental results of the first active geodesic laser gyroscope in China is reported. The pipe diaphragm is used to achieve single transverse mode, and the critical gain method makes the laser gyroscope single longitudinal mode operation become possible. Through the light intensity feedback control, the stability of the laser gyroscope signal is improved, which helps to accurately measure the angular velocity of the earth's rotation.

uC/OS-II is a small, but powerful preemptive embedded real-time operating system, which is mainly characterized by open source code, determined program running time and low requirements of hardware resources. Based on uC/OS-II operating system, the design scheme of spaceflight controller is introduced from three aspects. The first aspect mainly introduces the bottom transplantation strategy of uC/OS-II operating system, which mainly consists of four steps such as the coding of key transplantation files and the coding related to the porting target CPU. The second aspect is the design of board level drive layer. The third aspect introduces the detailed design strategy based on uC/OS-II operating system controller, in which application layer is mainly divided into several tasks, and being processed respectively according to the task priority. Finally, combining with the system requirements, the PC testing system is designed to test the parallel tasks. Experimental results show that the system can be running correctly and the expected function can be realized.

Aiming at the problem of video signal incompatibility and display resolution mismatch, a field programmable gate array (FPGA)-based video frame rate format conversion hardware structure system is designed. At first, the input video signal is decoded through the signal decoding module, and then the address multiplexing method is adopted to control two external storage devices such as DDR2 for frame rate conversion, at last, a look-up table is used to implement the bicubic interpolation algorithm to scale the image. The code multiplexing rate is improved and the computational complexity is reduced. And finally, the input video signal with 640×480 to 1 920×1 200 resolution range and VGA, AV, DVI transmission protocol being unified converted into LVDS output signal with 1 600×1 200 resolution, 60 Hz refresh frequency and 162 MHz pixel clock is realized. After experimental testing, the requirements of video format conversion and resolution enhancement can be fully met, and the problem of format incompatibility of data transmission in a wide range of applications can be solved.

In view of the random error caused by the vibration of synchronous motor when detecting the section distance of a laser displacement sensor, position sensitive device (PSD) photoelectric displacement sensor and raspberry are used to collect the error data. Taking the barrel equipment in the laboratory as an example, the curve fitting is carried out with Python, MATLAB and other software, and the collection and analysis of barrel data error are described. The basic flow of processing and curve fitting is analyzed, and the application of PSD in position error compensation is discussed. The barrel detection based on laser displacement sensor improves the reliability of detection data, reduces the error caused by vibration, and lays a foundation for subsequent data acquisition, processing and three-dimensional reconstruction.