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US 5,351,116 AGranted
Velocimeters
OwnerJames S. Barton, William K. D. Borthwick +3inventors
InventorsJames S. Barton, William K. D. Borthwick, David Harvey, Julian D. C. Jones, Roy McBride
Life of this patent
Estimating the term…
Abstract
A differential laser Doppler velocimeter is based on the use of a modified fibre optic Sagnac Interferometer 1,2. The interferometer phase is dependent not on the target displacement, but on its velocity. The output intensity of the interferometer may be modulated by control means PC which controls loop birefringence introducing a phase bias and polarization offset between counter-propagating beams.
Claims10
Apparatus for measuring velocity comprising:
- an interferometer including a loop of fibre optic radiation guide;
- means for launching optical signals from a source of radiation in opposite directions around said loop;
- probe means located within said loop and adapted to launch said optical signals from said radiation guide towards a moveable target, and to receive said optical signals after reflection from said target, and to re-direct said received optical signals into said radiation guide.
Dependencies are inferred from the claim text.