High-sensitivity roll-angle interferometer

Abstract

A roll-angle interferometer with high sensitivity is presented in this Letter. Two sets of centrosymmetric beams are used to travel through the measurement and reference arms of the roll-angle interferometer, which contains two specific optical devices: wedge prism assembly and wedge mirror assembly. Changes of the optical path in the interferometric arms caused by roll are differential and converted into phase shift through a particular interferometer system. The interferometric beams are a completely common path for the adoption of the centrosymmetric measurement structure, and the cross talk of the straightness, yaw, and pitch errors is avoided. The dead path is minimized, so the stability and the accuracy of the measurement can be greatly enhanced. The experimental results fit well with the theoretical analysis, and a measurement resolution of sub-microradian is achieved experimentally.

Development of a compact, fiber-coupled, six degree-of-freedom measurement system for precision linear stage metrology

“…As a result, a large body of work has been devoted to further improve the resolution and accuracy for displacement, [3][4][5][6] pitch and yaw, [7][8][9][10] straightness, [11][12][13][14] and roll. [15][16][17] In the referenced cases, the full calibration process may take multiple days since several setups and components are needed for multiple DOF measurements. Furthermore, extra calibration errors might be generated from these three areas: (1) temporal effects, where the increased time to calibrate exacerbates thermal drift; (2) dynamic errors, where the different sensor types have different masses causing a different dynamic behavior; and (3) location errors, where the sensor target must a) Electronic mail: xiangzhi.yu@rochester.edu.…”

Modeling and Analysis of Phase Fluctuation in a High-Precision Roll Angle Measurement Based on a Heterodyne Interferometer

“…It affords the advantages of high resolution, high noise immunity, and easy realization. Because it has recently become necessary to accurately measure the angular displacement measurement of a worktable in a high-end CN machine tool, the heterodyne interferometer has been also used to achieve a high-precision roll angle measurement [7,8,9,10,11,12]. A high-sensitivity measurement scheme for a small roll angle is shown in Figure 1, in which a phase retarder such as a half-wave plate (HWP) is adopted as the sensor for the roll angle test and a phase shift of the measurement signal and the reference signal is detected by a phase meter to demodulate the roll angle [8,9,10,11,12].…”

Enhanced roll-angle measurement interferometer

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] One of the most researched methods is based on optical heterodyne phase detection with a wave plate and polarizer. As a key part in such machines, a moving table along a specified axis has sixdegree of freedom errors, among which the roll-angle error has received more and more attention for lack of a suitable measuring method.…”

“…This method has been improved to achieve a higher sensitivity by using a quarter-wave plate to produce elliptically polarized light and a polarizer or a half-wave plate adopted as a sensor. Hou et al 13,14 have designed a roll-angle measurement system based on a differential plane mirror interferometer that has good stability and a measurement resolution of submicroradians. 5,6 Another technique based on propagation of polarized light is highly sensitive in a relatively large measurement range.…”