
Chapter 16
Elliptical Core and D-Shape
Fibers
Thomas D. Monte, Liming Wang, and Richard Dyott
*
KVH Industries, Inc., Tinley Park, Illinois
16.1 OVERVIEW
16.1.1 Elliptical Core Optical Fiber
Most polarization-maintaining (PM) fibers work on the basic principle of
creating two decoupled paths by introducing anisotropic stress generated by the
different thermal expansions of the glass materials across the optical core region.
In comparison, the elliptical core single-mode fiber employs the distinct property
of geometry or form birefringence, rather than stress, to achieve its polarization-
preserving characteristics. By separating the propagation constants ...