新型四象限设计及其光斑参数测量方法

针对自由空间光通信中对信标光进行快速、准确定位的要求,基于一种新型四象限探测器设计,提出了采用归一化函数方法获得光斑参数。首先,根据电流与相应光斑面积关系之比,可以得出光斑半径;其次,利用归一化函数的方法获得光斑中心偏移量的估计量;再次,采用查表法简化了函数的运算复杂度;最后,利用误差分析方法得出光斑中心偏移量的估计误差。理论分析和仿真表明,该方法能够精确地估计出光斑的半径和位置,光斑半径估计误差在±0.01%以内,光斑位置的估计误差在±0.005%以内。算法计算复杂度低,测量跟踪速度快,定位准确,可以广泛应用于自由空间光通信。

Novel four-quadrant design and the method for obtaining spot parameters

To make accurate and fast positioning in free space optical communications,a novel normalization function method to measure parameters of the spot which was based on a new four-quadrant detector design was proposed.First of all,due to the ratio of current to the corresponding spot area,the spot radius could be obtained.Then,based on normalization function method,the offset of the spot center could be obtained.After that,by using look-up table method,the computational complexity of the function was reduced.At last,the estimation error of the offset of the spot center could be obtained with error analysis.Compared with the traditional method,the proposed method has the advantages that it can obtain the spot radius quickly and easily,thus more information can be provided.Numerical simulations results and performance analysis show that the proposed method can accurately estimate the spot radius and the location.The estimation error of spot radius is only within the ±0.01%,and the estimation error of spot position is within ±0.005%.The proposed method has the advantages of low computational complexity,fast tracking speed and accuracy in spot positioning.It can be widely used in free-space optical communication.