To make the size, the heat sensitivity, and the like of an interferometer to minimum by constituting the interference arm of a first optical fiber extended between respective couplers combined with the respective clads of first and second optical fibers so as to contain compact bends.
This optical fiber Mach-Zehnder interferometer is formed out of first and second slender optical fibers 112, 114 having inner cores and outer clads and connected together through couplers 116, 118. The optical fibers 112, 114 are respectively provided with a first interference arm 120 and a second interference arm 122 extended between couplers 116, 118. The interference arms 120, 122 respectively contain compact bends 124, 126 positioned on the centers in bend of about 180°. It is desirable that the interference arm 120 and the compact bend 124 are set nest-likely inside the interference arm 122 and the compact bend 126. In such case, ambient air guiding light serves as the clad, and the fiber in the bend territory reducing the diameter serves as the core.
CRYAN COLM V
DARIOTIS STAVROS
MANTY MARGARET C
STOWE DAVID W
