反射型光纤信号干涉调制器

利用光纤传输系统中菲涅耳反射所产生的反射回波和多光束干涉效应设计了一种反射型光纤信号干涉调制器.实验中从X型光纤耦合器输入端输入光波,从输出端输出光波并入射到晶体表面上.将调制信号以电压形式加载于压电陶瓷管用共伸缩振荡来控制光纤端与晶体表面间距离,光信号在光纤端面与晶体表面发生菲涅耳反射产生的回波发生多光束干涉效应,实现对反射光的调制,从光纤耦合器的回波端输出被调制的回波光信号.这种光纤信号调制器主要针对光的振幅调制,实验中获得调制度约为44%,信噪比约为13 dB,带宽约为200 kH z.具有价格低廉、调制度高的特点,可应用于光纤传输信号的调制及信号斩波等.

A Reflection Interference Modulator for Signal in Fiber

Reflection interference modulator for optical signal in fiber transmission system was designed based on the multiple-beam interference effect of the echo wave which was aroused on the end face of fiber and the face of the crystal.In the experiment,the optical signal was input to a X-type fiber coupler,and the other input was used for the collection of reflective optical signal.The modulating voltage signal was amplified and drives the piezoelectric ceramic pipe vibrating in order to control the distance between the end face of fiber and the face of the crystal.As the same time,the multiple-beam interference occurs and the reflective optical signal was modulated.In the experiment,the device was operated for amplitude modulation,the modulation ratio can reach 44 %,S/N ratio is about 13 dB,and the bandwidth is about 2 000 kHz.This device has high modulation ratio and low price,and can be applied as a modulator or chopper was optical transmission system.