Title: Phase feedback fibre interferometer for surface profiling

Authors: X. Jiang, H. Martin

Addresses: Centre for Precision Technologies, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK. ' Centre for Precision Technologies, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK

Abstract: Advanced manufacturing techniques are producing increasing complex surfaces on the nano- and micro-scales. A fibre interferometer combined with a remote mountable optical probe is investigated with potential use for online measurement. The probe uses wavelength tuning to provide an optical |stylus| which sweeps the surface. The method requires stabilising against fibre path length change due to temperature drift and vibration. This is done by wavelength multiplexing two light sources into the same optical path and using one as a tracking interferometer. An electro-optic modulator is used as the actuator in a control loop using real-time calculated phase feedback. This technique also counters polarisation evolution effects in the apparatus. Experiments are carried out to analyse noise in the stabilised interferometric setup. A step height sample is also measured to obtain a comparison between the instrument and a commercially available product.

Keywords: surface metrology; fibre interferometry; phase shifting; precision engineering; surface profiling; precision metrology; optical probes; temperature drift; vibration; polarisation evolution.

DOI: 10.1504/IJPTECH.2011.039462

International Journal of Precision Technology, 2011 Vol.2 No.2/3, pp.246 - 265

Published online: 06 Apr 2011 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article