相干光通信中空间光混频动态特性及调控机制研究

The dynamic characteristics and the regulation mechanism of space hybird which is applied to coherent space laser communication are researched in this research project. The research results can improve performance and enhance the environment adaptability. Main research contents include: 1) By means of test and theoretic analysis, the various dynamic characteristics and influence law of factors are obtained. The relationship between errors in under the complex work environment and working process and all kinds of characteristics (including mixing efficiency, phase difference between IQ branches, phase jitter, delay time) is ascertained. Influence law of factors in the practical work is ascertained. 2) Based on the dynamic characteristics and influence law of internal factors, inhibition method or compensation method can be obtained. Signal light ratio regulation mechanism and control strategy can be confirmed with the analysis of the mathematical model and test. What is more, compensation hardware and adaptive control hardware and signal processing circuit will be determined. 3) Space hybird with adaptive control hardware will be designed and manufactured, which is applied to coherent space laser communication. Dynamic characteristics and adaptive control hardware will be verified. It is helpful to understand the mixing behavior and the universal law of space hybird at a deeper level in working process. Research results also can improve the system performance greatly and promote homodyne coherent communication system.

研究空间光混频器动态特性及性能调控机制的问题，并将其应用于相干空间激光通信系统，进而提升性能和提高环境适应性。主要研究内容包括：1）通过试验与理论分析获取实际工作中空间光混频器的各种动态特性与因素影响规律，明确动态工作条件和工作过程中引入的误差对空间光混频器性能（混频效率、IQ路相位差、相位及效率抖动量、响应延迟时间）的影响关系, 掌握空间光混频器动态条件下性能因素影响规律；2）基于动态特性及因素影响规律，寻找性能影响因素的抑制或补偿方法。同时通过数学模型和试验分析信号光分光比调控机制并确认分光比控制策略。进而确定影响因素补偿硬件和自适应调控硬件；3）设计并研制自适应调控光混频器的硬件，并用于相干光通信系统，完成特性及自适应调控验证。课题有利于在更深层次认识空间光混频器在动态工作过程中混频行为及其普遍规律，研究的成果也能较大提升系统性能并推进零差相干通信系统实用化。

空间光混频器是空间相干光通信领域的关键技术之一，本项目研究空间光混频器动态特性及性能调控机制，并将其应用于相干空间激光通信系统，进而提升性能和提高环境适应性，具体内容包括：①通过试验与理论分析获取了动态工作条件和工作过程中空间光混频器性能与主要特征，推导了复杂条件下空间光混频性能及通信性能模型。明确各种外部因素对空间光混频器性能的影响关系，并研究了影响因素性能补偿方法；②研究了分光比调控机制及控制策略。明确了分光比调控机制及对通信及锁相性能的影响，其中分光比为0.1时，灵敏度提高2.56dB，分光比为0.5时，锁相时间最短，锁相范围最宽。设计了分光比自适应控制系统，并给出了分光比在工作过程中控制策略；③提出并设计了包括空间耦合型、紧凑型、补偿型、分光比调控型、模分复用型在内的多种空间光混频器装置。并研制了空间耦合型光混频器及分光比控制硬件。另外也完成了空间光混频器性能及影响因素（大气湍流、像差等）实验研究。④实验研究基于空间光混频器的的零差相干通信实验，实验研究了星座图、眼图、接收灵敏度等参数。通过上述工作，从理论与试验两方面研究了空间光混频器动态特性及性能调控机制，说明研究成果可以提升性能和提高环境适应性。