Single polarization optical fibers and methods of fabrication
AssigneeBell Telephone Laboratories, Incorporated
InventorsIvan P. Kaminow, Vellayan Ramaswamy
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Abstract
Orthogonally polarized waves are more effectively decoupled in a waveguide that is fabricated in a manner so as to deliberately enhance stress-induced birefringence. This characteristic is accomplished by introducing a geometrical and material asymmetry in the preform from which the optical fiber is drawn. Three methods of preparing the preform are disclosed. Optical waveguides capable of transmitting power with only one direction of polarization are desirable for use with integrated optical devices which are polarization sensitive.
Claims7
A single polarization optical waveguide at least partially surrounded by an outer jacket having a different thermal expansion coefficient than said waveguide, and a thickness a along one direction that is different than its thickness b along a direction orthogonal to said one direction;
- characterized in that:
- the ratio of b to a is equal to or less than 0.1;
- and in that the induced strain birefringence .DELTA.n of the waveguide is greater than 5.times.10.sup.-5.
A method of preparing a preform comprising an inner core surrounded by a cladding, for the fabrication of an optical fiber having enhanced strain birefringence of greater than 5.times.10.sup.-5, characterized by the step of forming along diametrically opposed regions of said preform first portions of an outer jacket having a thickness that is greater than the cladding radius, and second portions of said jacket, located along said preform between said first portions, having a thickness that is less than the cladding radius.
Dependencies are inferred from the claim text.