Fiber optic sensors

Details Fiber optic sensors Fiber optic sensors

1989-01-13

1990-05-15

Sykes, Angela D.

Surgery

Truss

Pad

128675, 128748, 73705, A61B 502

Patent

active

049248707

ABSTRACT:
Serveral improvements in fiber optic sensing systems are disclosed. One improvement incorporates a dielectric filter applied directly to the sensing end of an optical fiber detector which has the characteristic that it reflects back a reference light beam of one wavelength while passing a sensing signal of a different wavelength which is modulated in some predetermined fashion beyond the filter. Both light signals are reflected back through the fiber and are, accordingly, attenuated in the identical or nearly identical fashion in response to various noise sources. The ratio of the intensity of the two signals is proportional to the sensed parameter and renders the system essentially self-compensating. The dielectric filter is preferably directly coated onto the exit end of the fiber through vapor deposition techniques. Time division multiplexing is used to sequentially fire plural light sources and a single photodetector is used for measuring the intensity of the reflected back signals of the various wavelengths. Another improvement encompasses the detection unit in which the input and reflected signals are separated using an off-axis parabolic mirror which provides excellent separation efficiency. According to another principal feature of this invention, a concave surface is formed at the fiber end which increases the numerical aperture of the fiber which provides greater sensitivity to the deflection of a pressure sensitive diaphragm spaced from the confronting the fiber end.

REFERENCES:
patent: 4588294 (1986-05-01), Siegmund
patent: 4593701 (1986-06-01), Kobayashi et al.
patent: 4691709 (1987-09-01), Cohen
patent: 4703757 (1987-11-01), Cohen
patent: 4711246 (1987-12-01), Alderson
patent: 4730622 (1988-03-01), Cohen
patent: 4787396 (1988-11-01), Pidorenko

Affiliated with

Also associated with

Rating

Fiber optic sensors does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Fiber optic sensors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fiber optic sensors will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-615600