【摘要】 光纤声光器件是基于光纤中的超声光栅引起的两个光波同向模式间的耦合 .此文比较了声切变波和疏密波激发的光纤超声光栅对双模光纤中对称模 L P0 1 、非对称模 L P1 1 间模式耦合的影响 ,得到一个重要结论 :除了光纤超声光栅的周期必须满足这两个耦合模式间的相位匹配条件外 ,该光纤超声光栅还必须要破坏这两个模式间径向电场的正交性 .这一结论为光纤声光器件控制光纤超声光栅产生有效的模式耦合提供了理论依据更多还原

【Abstract】 Fiber acousto optic devices are based on coupling between two copropagating modes caused by ultrasonic grating in the fiber. The different fiber ultrasonic gratings made of acoustic transverse and longitudinal wave result in the different mode coupling between LP 01 and LP 11 modes with different properties. This leads to an important result, that is, in order to make the two modes couple effectively, the fiber ultrasonic grating must disturb the orthogonality between the two modes in addition to the phase match condition. According to the result, the fiber ultrasonic grating caused by ultrasonic wave in the fiber can be selected to achieve effective coupling of the two fiber optic modes.更多还原