双折射双频HeNe激光器功率调谐纳米测量研究

Study of Displacement Measurement with Nanometer Resolution Based on Birefringent Dual frequency HeNe Laser Power Turning

:提出一种基于双折射双频 He Ne激光器功率调谐特性的纳米测量原理。当双折射双频He Ne激光器谐振腔长变化时 ,利用分裂的两个频率的寻常光 (o光 )和非寻常光 (e光 )功率调谐特性实现大范围里 λ/2 (约为 0 .3μm)低分辨率的测量 ,在 λ/2范围里用 o光和 e光的等光强点实现纳米级分辨率的测量。

A novel principle on displacement measurment with nanometer resolution based on birefringent dual frequency HeNe laser is presented.We transformed the displacement to be measured into the change of cavity length of a frequency split HeNe laser.Based upon intensity tuning characteristics of the two split frequencies (ordinary light and extraordinary light),we realized the measurement with λ/2(about 0.3μm)resolution and large measuring range (several millimeters).And in the measuring range of λ/2,we utilized the point where o light and e light have equal intensity to improve the resolution of measurement up to nanometer.With combining measurement of low resolution in large measuring range with high resolution in small measuring range,we demonstrated a new method for displacement measurement with nanometer resolution and relatively large measuring range.