Optical grating demodulator and sensor system

Details Optical grating demodulator and sensor system Optical grating demodulator and sensor system

1983-06-13

1987-05-26

Willis, Davis L.

Optics: measuring and testing

By particle light scattering

With photocell detection

250227, 250237G, G01B 902

Patent

active

046680934

ABSTRACT:
The demodulator system includes a source of light, and a beamsplitter which produces mutually coherent sensor and reference beams through sensor and reference fibers respectively, the sensor fiber being exposed to the effect to be sensed while the reference fiber is isolated therefrom. A ferrule maintains the output ends of the sensor and reference fibers in fixed positions with respect to a combiner lens which collimates the sensor and reference beams to form an interference pattern on a quad detector through a quad grating. The quad grating has four quadrants lined with the spacing of the interference pattern produced by mixing of the sensor and reference beams but positioned 0.degree., +90.degree., -90.degree., and 180.degree. apart in phase, .phi.. Therefore the quad detector produces outputs which contain +sine .phi., -sine .phi., +cosine .phi., and -cosine .phi. of the phase change between the sensor and reference beams due to changes in the effective optical path length difference between the reference and sensor fibers. These signals are then electronically converted into an electrical output which linearly represents the phase of the signal originally impressed on the sensor fiber.

REFERENCES:
patent: 2846919 (1958-08-01), Thompson
patent: 2848921 (1958-08-01), Koulikovitch
patent: 3983390 (1976-09-01), Llop
patent: 4039826 (1977-08-01), Wingate
Giallorenzi et al. "Optical Fiber Sensor Technology", IEEE J. Quant. Electron., vol. QE-18, No. 4, p. 654, Apr. 1982.

Affiliated with

Also associated with

Rating

Optical grating demodulator and sensor system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Optical grating demodulator and sensor system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical grating demodulator and sensor system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-700148