引言用激光进行干涉测量时常常需要在激光器和干涉仪之间加上一个光隔离器来消除光反馈，光反馈会造成激光输出功率的涨落。为此通常使用一种由偏振器和四分之一波长延迟器组合的系统。或使用法拉第旋转器。然而此两种隔离器均存在相同的缺点，即仅在某单一波长才有有效的隔离 INTRODUCTION Interferometry with lasers often requires the addition of an optical isolator between the laser and the interferometer to eliminate optical feedback, which can cause fluctuations in laser output power. A system of polarizers and quarter-wave retarders is usually used for this purpose. Or use a Faraday rotator. However, both isolators have the same drawback that only effective isolation at a single wavelength