提出了一种共光路外差干涉测量模拟磁头磁盘静态间隙的方法,该方法以低频差横向塞曼双频激光器作为光源,采用专门设计的双折射透镜分光和相位测量技术,实现了对光波半波长的3600细分,从而使测量分辨率达到0.1 nm。原理实验结果表明,该系统在无恒温的普通实验室条件下,1 h内稳定测量实验结果漂移小于4 nm；利用压电陶瓷(PZT)微动工作台(步进分辨率1 nm)驱动反射镜(模拟磁头)产生位移,在1 μm范围内与该系统测量结果进行比对,得到线性相关系数优于0.9998。

A novel method for measuring the simulated disk/slider stationary spacing is proposed in this paper, based on common-path heterodyne interferometry that utilises a transverse Zeeman laser with low beat frequency and a special designed birefringent lens (as beam splitter). The phase measurement technology is adopted to divide half wavelength of light by a factor of 3600, hence a resolution of 0.1 nm can be attained. The experimental results show that in ordinary laboratory condition, without air conditioning, the shift of phase measurement about the stability of system is approximately 4° in a hour, and calibration with a commercial PZT micro-drive working table (step resolution: 1 nm; extent: 1 μm) which drives a mirror (simulative slider), gives the linearly correlation coefficient of 0.9998.