双轴晶体锥光效应光盘径向寻迹研究

Disk Radial Tracking Based on Biaxial Crystal Conical Effect

根据晶体锥光效应提出一种光控制方法.在双轴晶体中光波沿光轴方向入射时,其传播方向随光偏振方向的不同而改变,通过控制磁光偏振调制器上磁场强度改变光的偏振方向,从而实现对激光束方向的控制.据此分析了双轴晶体锥光效应光盘寻迹的基本原理并设计出总体方案,数值模拟计算得到晶体入射光偏振角度与寻迹位移的关系,初步验证了此方案的合理性,该方案与传统机电跟踪寻迹方式相比具有结构轻巧,动态响应快等优点.同时,也为光开关、扫描等技术提供了一种新的思想和方法.

A new method of optical control is put forward based on conical effect in biaxial crystal.When the incident light spread along optical axis direction,the propagation direction will change with the polarization direction.By controlling the magnetic field on the magneto-optic modulator,the polarization direction can be changed,thus the laser beam direction control is realized.The fundamental of disk tracking is analyzed and overall plan is also designed,the relationship between polarizing angle and tracking displacement is obtained by numerical simulations,so this plan is reasonable.Compared with traditional tracking means of machine-electricity,this kind of plan has the following advantages：light weight,small volume and fast transient response.A new method for optical switch and scanning is provided meanwhile.