We describe a fibre-optic phase modulator comprising two coils of circular-core single-mode fibre wound onto two cylindrical piezo-electric elements, with a controlled angle between the axes of the cylinders. When this angle is optimized, the changes in retardation that accompany phase modulation are two orders of magnitude smaller than for a single element device offering similar phase modulation amplitude. © 1995.
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|Published - 1 Dec 1995