对现有强度调制型光纤麦克风做了分析和讨论，采用单模光纤(SMF)熔接多模光纤(MMF)的方法设计了一种新的反射式光纤麦克风。适当长度的折射率分布为抛物线形的多模光纤具有准直透镜的作用，直接熔接在单模光纤上，可以使光纤麦克风进一步微型化、成本低廉化。用单频正弦波信号做声源测试该光纤麦克风，输出正弦波电压信号与声源频率一致，振幅随声源振幅线性变化。结果表明，该结构的光纤麦克风在原理和实验上可以用于语音通信中。

Methods related to the design of intensity modulation fiber-optic microphone are reviewed. A novel scheme to realize the reflective fiber-optic microphone by using single-mode fiber (SMF) fusing multimode fiber (MMF) is proposed and verified experimentally. The MMF with appropriate length and refractive index of parabolic distribution has the function of collimating lens, which is fused with a SMF. For this fiber-optic microphone, the structure is secure, the volume is miniature, and the cost is low. Also there is no intensity noise caused by the instability of higher order mode. By using single frequency sine wave signal source, the fiber-optic microphone is tested. The frequency of output sine wave voltage signal is the same as that of the drive source, and the change of amplitude is linear. The results show that the fiber-optic microphone can be used for voice communication.