Abstract
We describe an extension of the active homodyne technique to produce stabilised, p/2 radian phase steps in a full-field interferometer. We have implemented the technique in a single mode fibre optic fringe-projector for shape measurement. The interference intensity (and hence phase) is maintained constant by feedback control to a phase modulator in one of the fibre arms. The feedback system has been modified to produce p/2 radian phase steps in the projected fringes. The phase stability and accuracy of each step was measured to be 17 milliradians in a 50 Hz bandwidth. The technique can be used to produce stabilised phase-stepped images in any fibre or bulk optic interferometer where active homodyne feedback control can be implemented.
| Original language | English |
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| Pages (from-to) | 174-180 |
| Number of pages | 7 |
| Journal | Proceedings of SPIE - the International Society for Optical Engineering |
| Volume | 4076 |
| Publication status | Published - 2000 |
| Event | Optical Diagnostics for Industrial Applications - Glasgow, UK Duration: 22 May 2000 → 24 May 2000 |