Page "Polarization-maintaining optical fiber" Paragraph 2

Several different designs of PM fiber are used.

Most work by inducing stress in the core via a non-circular cladding cross-section, or via rods of another material included within the cladding.

Several different shapes of rod are used, and the resulting fiber is sold under brand names such as " Panda " and " Bow-tie ".

The differences in performance between these types of fiber are subtle.

Some of the differences are explained in the article " PANDA-style fibers move beyond telecom ".