Heterodyne planar grating encoder especially insensitivity to grating tilts
Planar grating encoder,composed of one two-dimensional grating and the optical system (grating interferometer),is able to measure two-dimensional displacements.Grating interferometer errors are the errors caused by grating tilts,which possibly make phase changes of optical paths,and interfering beams non-parallelism.A new design of planar grating encoder based on optical heterodyne interferometry with a symmetric setup and double diffraction is proposed.It can measure the planar displacement with high resolution and high stability.With help of retro-reflectors,the tilts of the grating do not change the interference pattern and bring no measurement errors theoretically.The planar grating encoder has been set up,and the measurement results are compared with a two-axis laser interferometer.The repeatability of the grating encoder is about lOnm,and the laser interferometer comparing results confirm its error insensitivity to grating tilts.
Planar encoder two-dimensional grating heterodyne interferometer error reduction
Can Feng Lijiang Zeng Shiwei Wang
State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084, China
国际会议
2012第八届精密工程测量和仪器仪表国际研讨会(ISPEMI2012)
成都
英文
1-8
2012-08-08（万方平台首次上网日期，不代表论文的发表时间）