Interferometric fiber optic displacement sensor
Abstract
A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically.more »
- Inventors:
- Issue Date:
- Research Org.:
- Optisensors Inc
- OSTI Identifier:
- 63453
- Patent Number(s):
- 5420688
- Application Number:
- PAN: 7-990,622
- Assignee:
- PTO; SCA: 440800; 440600; PA: EDB-95:092588; SN: 95001401187
- DOE Contract Number:
- FG02-90ER81033
- Resource Type:
- Patent
- Resource Relation:
- Other Information: PBD: 30 May 1995
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; DISPLACEMENT GAGES; DESIGN; OPTICAL SYSTEMS; DIGITIZERS; INTERFEROMETERS; WAVE PROPAGATION; VISIBLE RADIATION
Citation Formats
Farah, J. Interferometric fiber optic displacement sensor. United States: N. p., 1995.
Web.
Farah, J. Interferometric fiber optic displacement sensor. United States.
Farah, J. Tue .
"Interferometric fiber optic displacement sensor". United States.
@article{osti_63453,
title = {Interferometric fiber optic displacement sensor},
author = {Farah, J},
abstractNote = {A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically. 29 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue May 30 00:00:00 EDT 1995},
month = {Tue May 30 00:00:00 EDT 1995}
}