Patent ID: 9255821
Filing Date: 2016-02-09
CPC Classification: G01D,G01H,G01J

Claim Text:
1. A fiber optic sensor for sensing an environmental effect, comprising: a sensing loop comprising an optical fiber having a first end and a second end; a first light source operative to produce first wavelength light; a second light source operative to produce second wavelength light; a first optical coupler operatively connected with said first light source that splits said first wavelength light into first and second optical waves; said first optical coupler operative to direct said first and second optical waves along a first optical path into said first and second ends of said optical fiber, respectively, such that said first optical wave propagates around said sensing loop to said second end of said optical fiber, said second optical wave propagates around said sensing loop to said first end of said optical fiber, and said first and second optical waves interfere at said first optical coupler to form a first combined optical wave; a second optical coupler operatively connected with said second light source that splits said second wavelength light into third and fourth optical waves; said second optical coupler operative to direct said third and fourth optical waves along a second optical path into said first and second ends of said optical fiber, respectively, such that said third optical wave propagates around said sensing loop to said second end of said optical fiber, said fourth optical wave propagates around said sensing loop to said first end of said optical fiber, and said third and fourth optical waves interfere at said second optical coupler to form a second combined optical wave; said second optical path being longer than said first optical path by a predetermined distance; a first detector operative to receive said first combined optical wave and output information regarding said first combined optical wave; and a second detector operative to receive said second combined optical wave and output information regarding said second combined optical wave.