A new type of translation–rotation encoder that makes use of two identical transparent dielectric gratings lighted in a −1-order Littrow mount is proposed. The correct choice of the wavelength-to-groove-spacing ratio produces only two transmitted beams, which interfere with the highest possible visibility in a large range of experimental conditions. Thus this mounting permits high-accuracy encoders to be produced by the use of cheap photoresist or plastic gratings and opens the way to industrial applications in high-precision mechanics, information processing, etc.
© 1999 Optical Society of America
(050.0050) Diffraction and gratings : Diffraction and gratings
(090.2890) Holography : Holographic optical elements
(120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
(230.0230) Optical devices : Optical devices
Michel Neviνre, Evgeny Popov, Bozhan Bojhkov, Lyubomir Tsonev, and Svetlun Tonchev, "High-Accuracy Translation-Rotation Encoder with Two Gratings in a Littrow Mount," Appl. Opt. 38, 67-76 (1999)