Development Of High Precision Adaptive Drive Control System For Thermo-optic Waveguide Delay Line

In all-optical communication networks and microwave photonic systems,optical delay lines,as the core components of channel matching,signal processing and other functions,have important engineering application value.The integrated optical waveguide delay line has become a research hotspot in this field due to its small volume and integration characteristics.The bit-type architecture based on the thermo-optic switch as the state switching component in the waveguide delay line has relatively good comprehensive performance,and the technical performance of the thermo-optic switch directly determines the core technical indicators of the delay line.In this thesis,the physical process of the instability of the operating point of the thermo-optic switch in the long-term work is analyzed.Based on the nonlinear theory of MZI modulation,a multi-cascade thermo-optic switch drive architecture is designed,and the system design and circuit parameter simulation are completed.The important parameters in the drive control system are tested,verified and optimized.The experimental results show that the system design can complete the working state switching drive of the bit-type waveguide delay line,and realizes the working state self-adaptation through the injection and detection of the perturbation signal,which ensures the stability of the switching performance.This thesis firstly investigates the working principle of a typical waveguide optical switch,analyzes the waveguide structure of the thermo-optic switch and the technical characteristics of mainstream materials,discusses the necessity of the research on the drive control system of the thermo-optic optical switch.Combined with nonlinear modulation theory,an adaptive drive control method for wave-thermal optical switches is introduced.Then,for the theoretical design and algorithm simulation of the adaptive drive control method,a high-precision adaptive drive control system based on time-sharing control is designed for the multi-cascade thermo-optic switch in the thermo-optic waveguide chip,and the program operation logic and work flow of the drive control system are discussed.The drive control system designed for this subject uses STM32 as the main control microcomputer,completes the hardware circuit design and simulation verification,and develops the actual drive control circuit.An experimental study is carried out for the control circuit using MZI electro-optical modulator as the switch analog component.Based on the measured results of the system,the hardware circuit of this subject is optimized and adjusted,and finally a better drive control effect is achieved.The system design and core operating parameters are verified.The experimental results show that for the thermo-optical waveguide switch,the driving perturbation injection technology scheme can be used to effectively control the operating point of the multi-level switch based on time-sharing detection.This process runs through the entire working cycle of the waveguide delay line,and can perform adaptive correction to compensate the influence of external factors on the optical device,so as to ensure the long-term stable operation of the waveguide delay line.