Multi-dimensional grating interferometer based on fibre-fed measurement heads arranged in Littrow configuration

Abstract

Industrial application versatility of interferometric encoders increases the urge to measure several degrees of freedom. A novel grating interferometer containing a commercially available, minimized Michelson interferometer and three fibre-fed measurement heads is presented in this paper. Moreover, the arrangement is designed for simultaneous displacement measurements in two perpendicular planes. In the proposed setup, beam splitters are located in the fibre heads, therefore the grating is separated from the light source and the photo detector, which influence measurement results by generated heat. The operating principle of the proposed system as well as error sources influencing measurement results are discussed in this paper. Further, the benefits and shortcomings of the setup are presented. A simple Littrow-configuration-based design leads to a compact-size interferometric encoder suitable for multidimensional measurements.

Research on automatic detection method for surface defects of large-size gratings

“…With the development of modern science and technology, large-size high-precision diffraction gratings play a decisive role in various industrial fields because of their optical properties of beam dispersion [1][2][3] , beam splitting, polarization modulation [4,5] and bit matching [6] . Due to the diffraction effect of gratings, the physical edge of the component is inconsistent with the optical edge [7] , which brings certain difficulties to defect detection.…”

Comparison of fiber interferometric sensor with a commercial interferometer for a Kibble balance velocity calibration

“…In particular, the ability for direct laser frequency modulation enables the use of various pseudo-heterodyne phase demodulation techniques, eliminating the need for a complex optical interferometer setup, since the second optical quadrature signal for the phase demodulation does not need to be acquired. This has led to the development of compact interferometer measuring heads that consist of only a fibercoupled collimator [15,16], or even just using a ultra-compact GRIN-lens collimator [17], pointing at the measurement surface, offering new possibilities for compact integration potential and potentially low cost.…”