Patent ID: 6233371
Filing Date: 2001-05-15
Classification: G02B,G02F

Abstract:
An apparatus comprising:a sections of a first optical fiber with inherent birefringence, the axes of the inherent birefringence having different refractive indices;a second optical fiber connected to said section of the first optical fiber to transmit light from the second optical fiber to the first optical fiber, or from the first optical fiber to the second optical fiber; andtwisting means for rotating the birefringence axes of said section of the first optical fiber with respect to said second optical fiber, wherein twisting means applies only twist to said second optical fiber without giving any squeezing on said second optical fiber;wherein said section of the first optical fiber is sized to provide phase delay equal to single or a multiple of quarter pi(.pi.) radian between two eigen polarization states defined by the birefringence axes.