The principle and structure of a new self-scanning laser interferomete
r are introduced. The output of a self-scanning photodiode array is mo
dulated to generate an ac measurement signal, thereby avoiding de drif
t and low-frequency disturbances. Experiments show that the device can
be used in the range of 100 mm and with a resolution of less than 0.0
2 mu m. (C) 1998 Society of Photo-Optical instrumentation Engineers.