The deepening of informatization requires the continuous improvement of the bandwidth, latency, rate and other performance of information technology, and the continuous decline in cost and power consumption. However, due to physical characteristics, electronic information technology is faced with many challenges, especially in the dimensions of bandwidth and power consumption. Making full use of the advantages of photons, we propose the convergence of photonics and electronics to enable information photonics playing a pillar role in technology fields such as connection/transmission, routing/switching, computation/processing and so on, and promote human beings from the electronic information age to the photoelectronic information age.

In the Visible Light Communication (VLC) system based on circle Color Shift Keying (CSK) modulation constellation, the bit error rate performance is poorer under certain number of modulation order. In this paper, we optimize the constellation point design, in keeping the constellation points under the condition of invariable pointing triangle center redesigned constellation structure. We change the constellation point location and increase the minimum code distance between constellation points to improve the bit error rate performance. In order to further improve the transmission quality of VLC signal, the principle of Finite State Machine (FSM) is introduced to carry out joint coding design to further improve bit error rate. Finally, simulation verification and performance analysis are carried out. The simulation results show that, compared with the traditional CSK modulation technology, the optimized extended circular constellation CSK and FSM combined coding proposed in this paper have better bit error rate performance. The gain of 4 Combination Coding-Finite State Machine(CC-FSM)code is 2.1 dB compared with that of 4-CSK, and the gain of 8CC-FSM code is 1.7 dB compared with that of 8-CSK.

According to the description of 50 Gbit/s-Ethernet Passive Optical Network (EPON) in IEEE 802.3ca new standard, multi-wavelength dynamic bandwidth allocation is needed in network uplink. In this paper, long short-term memory neural network is used to predict the network traffic in order to improve the efficiency of bandwidth allocation. At the same time, considering the different requirements of network delay and bandwidth for different types of services in the network, different allocation schemes are adopted for different priority services. The simulation results show that the neural network prediction method can effectively reduce the delay of the network. When different allocation schemes are adopted for different services, the latency of high-priority services decreases, and the latency varies with the increase of network load. The algorithm proposed in this paper meets the requirements of high-priority service. Although the latency of low-priority service is increased compared with the previous method, it has little impact on the overall service quality of the network considering that low-priority service does not have high latency requirements.

Carrier reuse technology is an important method to reduce the cost of Passive Optical Networks (PON) and multiplexing technology is the main method to improve the transmission capacity of PON. A PON system is designed in this paper. By combing the Subcarrier Multiplexing (SCM) and Wavelength Division Multiplexing (WDM) technology, the transmission capacity of PON is increased significantly. The passive reflection filter is used in the system to realize carrier reuse, which greatly reduces the system cost. In the SCM/WDM-PON system, the carrier reuse is achieved by the reflection filter, which is built in the Optisystem software. Using 3 and 6 GHz radio frequency signals as subcarriers in the SCM system, 8 wavelengths signal with a wavelength interval of 200 GHz ranging from 193.1~194.5 THz are used as optical carriers in WDM, and the data rate of users for uplink and downlink transmission is 1 Gbit/s. The effects of the reflection coefficient, optical carrier power and transmission distance on uplink and downlink data transmission performance are studied. When the reflection coefficient of the reflection filter is 97%, the overall system performance is optimal with the optical carrier power of 5 dBm and the transmission distance less than 27.2 km.

In order to maximize the total spectrum efficiency and improve the Quality of Experience (QoE) on Elastic Optical Network (EON), an adaptive modulation method based on Deep Neural Network (DNN) is proposed. Firstly, the network transmission quality in optical fiber is estimated. Then, the route length, hop number and video quality are taken as the three parameters of the request characteristics, and the deep learning method is adopted to selected the modulation system with the maximum spectrum efficiency according to the desired QoE of each requirement. The simulation results show that the average spectral efficiency of the proposed method is 51% and 32% higher in National Science Foundation (NSF) network than that of distance adaptive method and integer programming method, and 43% and 29% higher in China Network (CN)backbone network. In addition, the blocking probability of the proposed method is 0.01 lower than that of the distance adaptive method and integer programming method.

With the vigorous development of network technology, optical networks are developing in the direction of ultra-high-speed and large-capacity. Since the structure of the optical network is becoming more complex. the optical signal will inevitably suffer various impairments in the optical network. In optical communication equipment, the most important parameter of the physical layer is the Optical Signal-to-Noise Ratio (OSNR). Its value directly determines whether the service can operate normally. Once the requirements are not met, it will cause transmission errors or failures, reducing service quality, and transmission consumption. This paper proposes an accurate and efficient OSNR prediction method for optical communication nodes. By combining analytic prior knowledge methods and deep learning-based posterior knowledge methods, an optical communication node OSNR based on hybrid machine learning algorithms are proposed. The prediction method uses prior knowledge to reduce the training cost of neural networks and provides high-accuracy OSNR predictions. The result shows that the method proposed in this paper can provide high-accuracy machine learning models under more demanding conditions.

In view of the insufficient research on the vibration characteristics of the submarine cable fault signal, A three-dimensional finite element model of the optical fiber composite submarine cable (submarine cable) under the anchoring action is established. The simulation calculation is carried out under the anchoring conditions with a mass of 151.16 kg and a speed of 6.95 m/s. The acceleration data of the submarine cable optical unit is obtained in the X, Y and Z directions under the anchoring action. The vibration characteristics, including the amplitude frequency characteristic, energy entropy and kurtosis of vibration acceleration signal, are analyzed. The analysis of the vibration characteristics of the submarine cable under the action of anchoring provides a reference for the use of optical fiber technology to monitor the working status of the submarine cable.

In order to study the relationship between the macro-bending loss characteristics of the single-mode fiber and the temperature change, the thermo-optical effect and thermal expansion effect are corrected according to the theoretical formula proposed by Faustini L. Based on this formula, the macro-bending loss of SMF28 and 1060XP single-mode fiber with core-cladding-infinite coating structure under the influence of temperature is simulated and analyzed. The influence of temperature, wavelength, bending radius and other factors on the macro-bending loss of SMF28 single-mode fiber is explored, and the linear fitting results between the temperature and the two kinds of single-mode fibers are obtained. The results show that the macro-bending loss increases with the decrease of bending radius, and the increase of wavelength. The loss also decreases with the increase of temperature. Under certain bending radius and wavelength, the macro-bending loss and temperature are in monotonic relationship, which means increasing the number of bending turns can effectively increase the sensitivity to temperature.

A new method is proposed to solve the problem of finite-time synchronization transmission of signal in the current modulated semiconductor laser. Firstly, the characteristics of current modulated semiconductor laser are analyzed theoretically. Then, the unique sliding mode surface and sliding mode controller are designed to achieve the finite-time synchronization transmission of the target signal by using sliding mode control method. The results show that the technology can not only ensure that the current modulated semiconductor laser can complete the synchronization transmission of the target signal in a finite time, but also control the convergence speed of the sliding surface by simply adjusting the parameter in the sliding surface. In the meantime, the technology has no restrictions on the target signal.

In view of the common problems of fiber surface plasmon resonance sensor with weak strength, low sensitivity and low plasma excitation efficiency, this paper proposes to use the long-period fiber grating as an auxiliary platform to study the ways of enhancing the sensitivity of surface plasmon resonance sensors. A layer of gold film is thermally evaporated on the sensing area of the fiber grating surface, and the external sensing performance is enhanced by tuning the polarization mode of the input fiber grating. We choose the sodium chloride solution as the external refractive index sensing material, and conduct a simulation through software. The results show that before and after the gold coating, the transmission power of the transverse magnetic wave and the transverse electric wave are attenuated by 4.3 and 0.3 dB in the air, and 5.3 and 2.2 dB in the solution. Within the range of refractive index change of the solution from 1.335~1.372, the refractive index sensitivity of the two polarized light sources increased by 18.7 and 12.9 nm/RIU, respectively.

In order to solve the problem of limited bandwidth and large overall size of leaky-wave antenna, a new wide-band leaky-wave antenna is proposed in this paper. The antenna is composed of surface plasmon polaritons transmission lines and asymmetric circular patches. It works at 7 ~ 15 GHz (relative bandwidth of 72.73%), enabling continuous beam scanning from backward to forward with a beam scanning angle of 69 ° and a stable high radiation gain. The maximum gain of the antenna in simulation reaches 13.1 dBi and the measured gain variation is only 1.64 dB. The test results are good agree with the simulation results. The proposed leaky-wave antenna has the advantages of simple structure, stable performance and easy fabrication. Furthermore, the overall size of the antenna is comparatively small, which makes it conducive to the conformable integration in wireless communication systems.

Although millimeter-wave communication technology can meet the design indicators of 5th Generation Mobile Networks (5G)communication, the path loss of millimeter-wave in the transmission process seriously affects its transmission performance. Therefore, waveform shaping technology is needed to concentrate the transmission energy to reduce the impact of path loss. However, the traditional Discontinuous Reception (DRX) mechanism will lead to beam misalignment in the beam shaping system, which is no longer applicable in 5G system. In order to solve the above problems, this research proposes a long-period Adjustable Orientation DRX (A-ODRX) mechanism. The beam search state is merged into the long period state to overcome beam misalignment, and a long period incremental coefficient is introduced to save power consumption. The semi-Markov chain and the European Telecommunications Standards Institute (ETSI) traffic model are used to simulate the A-ODRX mechanism. The average delay, energy saving effect and beam misalignment probability of A-ODRX mechanism are analyzed in simulation. The results show that the A-ODRX mechanism can significantly reduce the beam misalignment probability while effectively reducing the energy consumption of the terminal.