A section of birefringent optical fiber spun at a slowly varying spin-rate from zero to a high value, or vice versa, behaves as a fiber-optic quarter wave plate in polarization transforms. The compounds may be used to treat diseases or conditions such as those associated with bone, cancer, or pain. The separator may be operated in any vertical, horizontal or oblique orientation, or within devices whose orientation varies over time. Area of each rectangular patch is suitably reduced and reproduced onto a photomask.