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 10nm, and the laser interferometer comparing results confirm its error insensitivity to grating
tilts.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.