Analysis of nonlinearity in a high-resolution grating interferometer

✍ Scribed by Dejiao Lin; Hong Jiang; Chunyong Yin

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 301 KB
• Volume: 32
• Category: Article
• ISSN: 0030-3992
• DOI: 10.1016/s0030-3992(00)00022-0

✦ Synopsis

Metrological feasibilities of a high-resolution grating interferometer (GI) based on a transverse Zeeman laser are investigated. When the grating pitch equals 20 mm, a resolution of 0.7 nm is obtained by means of a heterodyne signal processing method. The comparison of two approaches for determining the residual nonlinearity is presented. One is to evaluate the maximum residual error by determining the amplitude modulation degree of the measurement signal. The other is to do a high precision calibration with a dierential dual-frequency interferometer that has a higher precision. The experimental results show that the nonlinearity is no more than 25 nm which ®ts well with the estimating result. Analysis of the depolarization eect of the grating indicates that it has little in¯uence on the measurement accuracy.