The operation and maintenance personnel of transport network need a integrated system to manage 5G transport net-work. This system needs to include software defined network (SDN）controller, automatic switched optical network (ASON）control I management plane and network element management system I network management system (EMS I NMS） function. Based on thisrequirement, according to the concept of management and control system (MCS , this paper discusses the evolution trend and architecture of existing network management technology to MCS, andintroduces its new functional features, such as u-nified graphical user interface platform, unified network element access mode, unified object data model and functional module, openapplication programming interface, flexible deployment on cloud, enhanced security management and intelligent operation and maintenance.

With the gradual expansion of the application of fiber Bragg grating（FBG）, the requirements for accuracy, stability and real-time of the sensing system are increasing. In thispaper, the signal processing methods for the accuracy and reliability of FBG sensing systems are reviewed. The accuracy-related includes denoising algorithm, peak detection algorithm,multi-peak decomposition and multiplexing, and the calibration method to improve the reliability of the system are summarized. The theory and application of related signal processingalgorithms in the past ten years are mainly introduced, and the existing problems and development trends are analyzed.

To explore the applications of time of flying technology for short to medium distance measurement, a scheme for optical fiber refractive index and length measurement is introduced, which is based on the TDC7201 chip that apply time of flying technology principle. The measureme nt system is made up of some devices and modules, such as TDC7201, microcontrolle r, laser transmitter and laser receiver, and the fiber length measurement range is 2 cm to 100 km in theory. The experiment platform is established, and then the refractive index or length of 1 cm, 2 cm, 3 cm and 1.5m, 5.1m, 20 km, 70 km, 90 km fiber are measured. The result shows that the minimum measurement length is 1 cm, the maximum measurement length over 90 km, and the standard deviation of 5.1 m fiber length measurement is 0.9 mm.

In order to obtain photonic crystal fiber with high birefringence and low loss, an elliptic double core photonic crystal fiber with triangular lattice arrangement is designed. The relations between the air hole pitch of the fiber and birefringence, non-linearity characteristic, mode field area, confinement loss and dispersion is studied by using the full vector finite element method. The results show that the birefringence of the fundamental mode of the fiber reaches 0.04343 at the wavelength of 1.55 μm, and the nonlinear coefficients in X and Y polarization directions are 48.832 w -1.km-1 and 46.286 w-1.km-1 respectively. At the same time, the confinement loss in the X direction is as low as 8.242 ×10-9 dB/km. In the wavelength range of 0.85～1.8 μm, the disper-sion is normal negative dispersion.

In order to meet the increasing bandwidth requirements, the next generation access network is required to support each wavelength transmission speed exceeding 50 Gb/s, while ensuring the coexistence of traditional network in an economical and efficient manner. Advanced modulation and detection technologies based on digital signal processing is a powerful support to achieve this goal, which can provide good support for large-scale, multi-scene and multi-service access. The principle and main characteristics of several new multi-carrier modulation technologies are discussed in this paper, and their research status and existing problems in passive optical network（PON） are reviewed. What’s more, the suggestions on research direction based on the appeal of the next generation PON are put forward.

In order to obtain the optimum transmitting power required to reach the maximum transmission distance under nonlinear constraints, makes it possible for software to customize optical access network. For the commercial wavelength division multiplexing passive optical network (WDM-PON）with STM-16 and STM-64 of external modulators are modeled and analyzed under different wavenumbers (4λ, 以 λ and 16λ）, The power of optimum transmitting and maximum transmission distance are analyzed, respectively. Network model were composed of standard single-mode fiber SSMF-2以, 1 :64 passive fiber branching at its far end (RN）, optical line te rminal (OLT）and optical network unit (ONU）. In order to improve the network utilization and receiving efficiency, the influence of different wavenumbers and transmission distances on the performance of high data rate WDM-PON system is analyzed. In order to save power consumption, the configuration of each multi-band PON is optimized in terms of transmission power.

In order to further improve the transmission capacity of the optical communication system, this paper proposes a two-wavelength ×three－mode hybrid multiplexer/demultiplexer based on photonic crystals. The device consists of three combined resonators, three wavelength selective reflection microcavities, single mode waveguides, multimode waveguides and tapered coupled waveguides. The filtering is realized by the structure of combined resonator and wavelength selective reflection microcavity, and the mode conversion is realized by the structure of the asymmetric parallel waveguide. The simulation analysis by time-domain finite difference method shows that the device can realize the multiplexing/demultiplexing of six channels, such as the 1530 nm TE 0 mode, 1530 nm TE 1 mode, 1530 nm TE 2 mode, 1550 nm TE 0 mode, 1550 nm TE 1 mode and 1550 nm TE 2 mode. Its insertion loss is <0.127 dB and the channel crosstalk is <-15.19 dB.

According to the study of two existing athermal compensation scheme s, a new athermal arrayed waveguide gratings (AWG）temperature compensation structure has been presented to solve the problem of miniaturized packaging of athermal module in this paper, which is based on the bimetallic strip and the me tal plate. The theoretical calculation results show that linear wavelength shift can be completely compensated. In addition, the length of the metal plate was reduced to 1/4 of the original one, enabling the module to be miniaturized. This structure can adapt to the wavelength shift of the AWG chip by adjusting the thickness, width of the bimetal, and the length of the metal plate, which improves the design flexibility.

In order to obtain L-band Q-switched pulse, this paper designs Q-switched laser based on Propyl alcohol saturable ab-sorber, the saturable absorber is made of organic solution Propyl alcohol, and the modulation depth of the saturable absorber is measured to be 5.58%. The L-band pulse is obtained by applying saturable absorber to Q-switched laser. The average output pow-er of the Q-switched fiber laser is 0.79 mW with the pulse repetition rate of 20.9 kHz and the pulse energy is up to 36.7 nJ when the pump power of the laser is 230 mW.

Facing the application scene which is hard to obtain the offset working point information from signal light, a kind of repetition-frequency optical shaping scheme with reference light is proposed after analyzing the output performance of different wavelengths of signal light passing through the intensity modulator. The wavelength division multiplexer is used to import and separate the reference light. Benefited from the relevance of output laser of different wavelengths passing through the intensity modulator, it is possible to obtain the offset working point information of signal light based on the intensity of reference wave. It is possible to obtain the offset working point information effectively in the scheme and is not effected by signal light change.

Aiming at the problem of weak light signal detection and temperature influence in compleX environments, a design scheme with MSP430 as the core controller, avalanche diode（APD）as the sensor and long rang radia（LoRa）technology as the data transmission is proposed. This circuit uses a bias adaptive temperature compensation circuit to make the bias voltage change with temperature, so as to stabilize the APD gain. The eXperiments show that the APD boosting is less affe cted by the tempera-ture compensation circuit and the gain is stable at 100 ±5 dB. At the same time, the scheme detects the weak light signal with an error of less than 3.92% and can remotely monitor the weak light intensity change in real time within 10 km of a plant area.

Aim to the application of smart street lamp and internet of vehicles, a communication model of street lamp based on visible light-emitting diode （LED) is designed. Firstly, the illumination pre-equalization method of LED single channel stability and multi-channel stability is proposed, and the receiving effect is tested. Secondly, according to the installation methods of uni-lateral, bilateral symmetrical and bilateral asymmetric street lamps, the spatial illumination distribution mathematical models of three kinds of street lamps are constructed and simulated by Lambert model, and the average illumination in the near ground are a of the road is analyzed. Finally, the vehicle receiving model of visible light signal and the color division multiplexing (CDM) visi-ble light communication model from LED street lamp to vehicle are designed, and the signal receiving waveform of the model and the multipath effect of the model are analyzed.

In order to balance the peak-to-average power ratio (PAPR）and high complexity of coherent optical orthogonal fre-quency division multiplexing (CO-OFDM）, a novel joint algorithm based on active constellation extension-projection onto con-vex sets (ACE-POCS）and iterative partial transmission sequence (IPTS）is proposed, which is called the improved iterative par- tial transmission sequence of active constellation extension (ACE-IPTS）. The simulation results show that, compared with the o-riginal signal, the PAPR0 of ACE-IPTS algorithm is optimized by 4.907 dB. ＼hen the bit error rate is 10 -3, the optical sig-nal-to-noise ratios (OSNRs）of ACE-IPTS and improved ACE-POCS increase by 0.54 dB and 1.04 dB respectively compared with the IPTS algorithm. The calculation times of IPTS, ACE-IPTS and ACE-POCS are 59392, 79872 and 204800 respectively. Compared with ACE-POCS algorithm, the calculation times of the ACE-IPTS algorithm decreases by 61%.