Design of highly birefringent fibers to optimize or minimize pressure-induced birefringence

A simple formula is derived to describe the effect of radial pressure on the birefringence in a coated birefringent optical fiber. Both plastic and metal coating materials are studied. Theoretical analysis shows that the pressure-induced birefringence in the fiber is determined mainly by the elastic properties of the fiber glasses and is rather insensitive to the coating material and thickness. The condition for zero pressure sensitivity is found to be strictly independent of the coating parameters. The use of boron-doped stress-applying sections to optimize the pressure sensitivity of a silica fiber is discussed.<
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