Abstract

This paper describes a system of interferometric control as applied to the smaller ruling engine of the Mount Wilson Observatory. The usual mechanism intermittently advances the grating carriage with a spacing closely approximating an integral number of fringes of green Hg¹⁹⁸ light. A Michelson interferometer monitors this motion. The interferometer is modulated by deflecting the compensating plate electromagnetically, thus correcting for barometric pressure changes and also causing the fringe pattern to oscillate with a small amplitude at 60 cps. The oscillating fringe pattern is scanned by a phototube and is reproduced on a monitoring cathode-ray tube; any decentering of the nth fringe is detected by synchronous demodulation and is converted to a stored electrical charge. During each spacing operation, a differential correction proportional to the stored error signal is introduced into the mechanism. Corrections average about 1 centifringe (2.5 × 10⁻⁷ cm). The system is relatively simple and ensures a very high order of precision in spacing, with extremely straight grooves.

© 1962 Optical Society of America

Interferometric Calibration of Precision Screws and Control of Ruling Engines

George R. Harrison and James E. Archer
J. Opt. Soc. Am. 41(8) 495-503 (1951)

Interferometric Control of Grating Ruling with Continuous Carriage Advance*

George R. Harrison and George W. Stroke
J. Opt. Soc. Am. 45(2) 112-121 (1955)

Correcting groove error in gratings ruled on a 500-mm ruling engine using interferometric control

Xiaotao Mi, Haili Yu, Hongzhu Yu, Shanwen Zhang, Xiaotian Li, Xuefeng Yao, Xiangdong Qi, Bayinhedhig, and Qiuhua Wan
Appl. Opt. 56(21) 5857-5864 (2017)

300  mm ruling engine producing gratings and echelles under interferometric control in China

Xiaotian Li, Haili Yu, Xiangdong Qi, Shulong Feng, Jicheng Cui, Shanwen Zhang, Jirigalantu, and Yuguo Tang
Appl. Opt. 54(7) 1819-1826 (2015)

Ruling Engine with Hydraulic Drive

W. R. Horsfield
Appl. Opt. 4(2) 189-193 (1965)