多模激光调节相干长度外差干涉技术

An Optical Heterodyne Interferometer Using a Multi-mode Laser Source to Modulate Coherent Length

研究了一种采用多模半导体激光与耦合光纤、采取声光调制及调节相干长度的外差干涉系统。该系统具有功率大、分辨率高、测头小、不接触等优点。实验证明，该系统达到优于１ｎｍ的分辨能力，可用于人体耳膜振动特性的测试与研究。

This paper describes a measuring system basing on an optical heterodyne interferometer, which utilizes a multi-mode laser diode and coupled optical fibers to adjust the coherent length of the system. The sensor is small and works under a non-contact condition. It is proved experimentally that this system's resolution reaches into quasi-nm,making possible the detection of the vibrating characteristics of the human ear membrane.