Patent ID: 6801319
Filing Date: 2004-10-05
Classification: G01C

Abstract:
A fiber optic gyroscope comprising:a loop including a single mode optical fiber having a first end and a second end; and a depolarizer region coupled to said loop, said depolarizer region comprising: a first optical fiber section; a second optical fiber section coupled to said first optical fiber section via a first splice; a third optical fiber section; a fourth optical fiber section coupled to said first optical fiber section via a third splice; wherein said first optical fiber section is coupled to said first end of said loop via a second splice; said third fiber section is coupled to said second end of said loop via a fourth splice; said first optical fiber section has a length y, said second optical fiber section has a length w, said third optical fiber section has a length z, and said fourth optical fiber section has a length x and wherein x+z is substantially equal to w+y; wherein w>x and z>y; said first, second, third and fourth fiber sections comprise polarization maintaining fibers; said first splice having an alignment between 35Â° and 55Â° between a major axis of polarization of said first optical fiber section and a major axis of polarization of said second optical fiber section; and said third splice having an alignment between 35Â° and 55Â° between a major axis of polarization of said third fiber section and a major axis of polarization of said fourth fiber section, whereby thermal and mechanical influences on the optical path lengths of each one of said optical fiber sections are substantially the same.