High speed wavelength division multiplexing distributed feedback (DFB) laser is the core device of data communication, and its reliability affects the reliability of the whole communication system. Two burn-in experiments and failure analysis are carried out on the self-developed 25 Gb/s 4-wavelength coarse wavelength division multiplexing(CWDM4) DFB laser, and the working life of the laser is calculated by the three-temperature method. The experimental results show that the burn-in method combining light acceleration(25 ℃, 100 mA) and temperature acceleration(100 ℃, 75 mA) can effectively stimulate the early failure characteristics of weak lasers, the three-temperature method is used to estimate the actual lifetime of the laser at 60 ℃ and 45 mA for a long time to be at least 17 years.

In order to effectively simplify the preparation process and reduce the preparation difficulty of surface grating coupler, a highly efficient silicon nitride surface grating coupler compatible with complementary metal oxide semiconductor(CMOS) technology is designed. The coupler structure is modeled, optimized and simulated using two-dimensional finite difference time domain(2D-FDTD) algorithm. The spectral characteristics of couplers with different structures are calculated and compared. The research results show that the designed silicon nitride surface grating coupler on the standard silicon on insulator(SOI) wafer, with the help of CMOS back channel process, has a maximum coupling efficiency of - 3.36 dB and a bandwidth of -3 dB of 101 nm near the communication wavelength of 1550 nm.

In order to improve the communication rate and expand the channel capacity, an integrated device using width modulation(WM) resonator and nanowire waveguide is proposed to couple the electro-optical modulation module and the mode division multiplexer module. The principle, structure design and performance of the electro-optical modulation module and the mode division multiplexer module are introduced in detail. The Lumerical software is used for simulation and tolerance analysis. The simulation results show that when the working wavelength of the integrated device is 1550 nm, the electro-optical modulation can be performed first, and then the TE0 mode and TE1 mode can be multiplexed. The insertion loss of the two modes is 0.186 dB and 0.18 dB respectively, the extinction ratio is 29.6 dB and 24.5 dB respectively, the channel crosstalk is -49.57 dB and -49.12 dB respectively, and the modulation depth is 0.999.

In the traditional calibration method, the in-phase quadrature(IQ) modulator has the problems of slow calibration speed and the data is complex and difficult to process. In some practical applications, it is impossible to provide quadrature radio frequency signals with an amplitude of twice the half-wave voltage. In order to solve these problems, a rapid fine calibration method based on modulation phase for IQ modulator is proposed, which can achieve fast and accurate calibration of IQ modulator bias voltage without adding radio frequency. The test results show that this method can complete the calibration of IQ modulator in about 45 s, and the calibration accuracy is high, and the resolution is 10 mV. The IQ modulator can be directly controlled to generate single sideband signal with suppressed carrier.

Scale factor is a key indicator for evaluating the dynamic performance of fiber optic gyroscope, its error directly affects the precision and stability of fiber optic gyroscope. Because the area of the gyroscope fiber optic sensing coil is positively related to the temperature due to the thermal expansion and cold contraction effect, a linear compensation method is proposed to compensate the gyroscope scale factor error using the temperature characteristics of the light source, which makes the temperature compensation effect of the subsequent fiber optic sensing coil is the best. The experimental results show that, in the range of 100 ℃ (- 40~+60 ℃), the scale factor error of fiber optic gyroscope is reduced from 1100ppm to 620ppm after using this method, which greatly improves the temperature stability of fiber optic gyroscope scale factor (before temperature compensation of fiber optic sensing coil).

In order to improve the secrecy transmission performance of visible light link, based on the analysis of link secrecy capacity under static and dynamic optical beam configurations, a security performance enhancement method of visible light communication physical layer based on dynamic vertical non-Lambertian beam is proposed, which selects the vertical candidate beam dynamically according to the different emitter, secrecy user and position relationship of eavesdropper. Quantization results show that, in a typical indoor environment, compared to a conventional static Lambertian beam configuration, the average secrecy capacity gain based on dynamic vertical non-Lambertian beam configuration is up to 3.03 b·s-1·Hz-1, and the gain ratio is up to 86%.

In order to improve the channel capacity, data transmission rate and spectrum efficiency of deep space inter satellite optical communication, this paper designes the deep space inter satellite optical communication link, builds the deep space inter satellite optical polarization multiplexing(PDM) system. Combined with the link characteristics of laser communication, the performance of PDM system link at different communication wavelengths and different transmission speed are simulated. The results show that the PDM technology can effectively improve the data transmission rate, and also helpful to improve the performance of deep space optical communication system.

For the problem of low communication capacity and low confidentiality of radio frequency(RF) communication, combined RF system and multiple input multiple output free-space optical(MIMO-FSO) system, this paper proposes the RF/MIMO-FSO hybrid communication system. Based on the analysis of RF system, MIMO-FSO system, single input single output (SISO)-FSO system and RF/MIMO-FSO hybrid communication system models, the bit error performance of the these four systems is compared through simulation. The result shows that compared with RF system and SISO-FSO system, the bit error performance of RF/MIMO-FSO hybrid communication system is significantly improved, it is about 3 orders of magnitude higher than SISO-FSO system on average under adopting the same modulation mode.

In order to improve the positioning accuracy of the laser spot center and realize the function of laser stabilization output, this paper proposes the laser stabilization integrated system based on four-quadrant detector. First, according to the working principle of the four-quadrant detector, theoretical calculates and analyzes the center position and deviation of spot on the four quadrant detector, then, combines the computer signal processing technology and control technology, closed-loop control of the four-quadrant detector signal acquisition device and integration of the four-quadrant detector and optical components in a multi-axis cage structure, completed the design of the laser stabilization integrated system. experimental data result for many times show that the system can 100% complete the positioning of the spot center and the stability can reach 94.74%, the maximum difference of the experimental error is 2.422 μm.

In order to make full use of the frequency band resources in radio-over-fiber(RoF) system, a frequency multiplier tunable RoF system based on Mach-Zehnder modulator(MZM) is proposed, the techniques of wavelength selection, coherent detection, wavelength reuse and digital signal processing(DSP) are used to achieve the output of signals with different octave factors in the uplink and downlink of the RoF system. The simulation results show that when the RoF system transmits hexadecimal quadrature amplitude modulation(16QAM) signals, the multiple frequency multiplier factor can be realized in both the upstream and downstream links, and the minimum vector error ranges of downlink transmission and uplink transmission are 5.5% ～ 7% and 6.4% ～ 8.6% respectively.

In order to improve the flexibility of the communication system, expand the application range and reduce the construction cost, a full-duplex radio-over-fiber system with multi-band signal output is proposed in this paper. Under the condition of single light source, this paper realizes the downlink vector signal transmission in three different frequency bands by flexibly controlling the angle of polarization controller and linear polarizer. Using carrier reuse and coherence detection technology, uplink baseband signal output is realized. The simulation results show that for the 6 Gb/s hexadecimal quadrature amplitude modulation(16QAM) signals are transmitted through 30 km optical fiber, the minimum error vector amplitude(EVM) of the output signals in 5 GHz, 45 GHz and 25 GHz bands in the downlink are 5.66%, 4.03% and 2.67%, respectively. The minimum EVM of the uplink output signal is 4.01%.

Aiming at the problem of optical network security protection, the anti-interception transmission technology of quantum noise random encryption(QNRC) physical layer is deeply studied from two aspects of physical layer security evaluation and experimental verification. Firstly, the development status of QNRC at home and abroad is introduced, and a set of general methods for physical layer security evaluation is summarized. Then, An experimental scheme of intensity shift keying quantum noise random encryption (ISK-QNRC) based on optical domain decryption is proposed. Aiming at the manufacturing process problems of high resolution and high sampling rate digital to analog converters in the scheme, a parallel ISK-QNRC scheme is proposed and verified. The results show that the scheme is safe and effective in information transmission. Finally, the typical application scenarios and development trends of QNRC technology are analyzed.

The high sampling rate and high resolution digital-to-analog converter(DAC) is one of the core components to improve the performance of quantum noise random encryption(QNRC) system, which has been restricting the development of QNRC system technology. In order to explore the effects of different DAC sampling rates and resolutions on the performance of the QNRC system, the VPItransmission Maker Optical System 9.1 software is used for system simulation design. Firstly, a QNRC ststem basded on phase-shift keying modulation with mesoscopic power of -21 dBm, transmission distance of 1000 km, transmission rate of 10 Gb/s and number of ciphertext states of 28-1 is built. Then, the sampling rate and resolution of DAC are changed to compare and analyze the performance of QNRC system. The analysis results show that when the DAC sampling rate and resolution are 30 Gb/s and 6 bit respectively, the QNRC system has the best cost-performance ratio.

In order to effectively detect the strain of oil pipeline, Firstly, the finite element software is proposed to apply load to the oil pipeline with support and hanger structure, and the strain distribution on the surface of the pipeline is simulated to optimize the strain detection arrangement mode of the distributed optical fiber oil pipeline. Then, the sensing fiber is pasted to the outer surface of the pipeline along the axial direction. The strain distribution on the pipeline surface is monitored in real time by measuring Brillouin frequency shift by brillouin optical time domain analyzer(BOTDA). Comparing the simulation and experimental data, it can be known that the top and bottom of the pipeline are sensitive to strain, and the simulation result of the strain distribution on the pipeline surface are basically consistent with the experimental measurement.

Based on the three application requirements of "high speed, intelligence and autonomy", this paper presents the general architecture of the new generation optical cable communication network. The transmission system and key technologies of optical cable communication network backbone layer, the transmission system and key technologies of optical cable communication network access layer, the management and control architecture and key technologies of optical fiber communication network are analyzed, the autonomous controllable structure and development suggestions of optical cable communication network are introduced. It can provide some reference and guidance for the planning and construction of optical cable communication network and the development and application of optical communication equipment.

As the cable is soft, it is easy to bend in engineering operation, so that the bending radius of the cable equipped in the spacecraft cabin is too small. In order to enhance the rigidity of optical cable, a reinforcement design scheme for aerospace optical cable and optical cable components is proposed. Without changing the structure of optical cable, after the optical cable components are manufactured according to the original production process, tape and cloth are used for winding protection, and the correlation of optical cable components is tested and analyzed. The test results show that the scheme enhances the overall rigidity of the optical cable assembly and meets the design requirements.

Audio video bridging(AVB) communication process involves a large amount of data, and each packet of AVB data can reach thousands of bytes. When unmanned vehicles are divided by the concept of domain, the communication between domain systems will cause the huge amount of datas transferred to the decision-making layer and the extremely low processing efficiency due to the huge amount of datas transmitted by AVB and the fast transmission speed, the actual decision-making layer only needs to process the payload datas in the AVB. In order to ensure that the effective datas required for decision-making layer are only the effective datas of each packet of AVB, design a Hash address filtering algorithms and improved sliding window algorithms to extract the payload datas, and use a virtual communication and physical communication method to strip the proposed effective the data is sent to the decision-making layer. This method reduce the amount of datas processing at the decision-making layer effectively, improved its datas processing efficiency, and meet its datas real-time processing requirements.