Form birefringence in UV-exposed photosensitive fibers computed using a higher order finite element method

Abstract

The effective index change and form birefringence are calculated in UV-exposed fibers using a high-order vectorial finite element method. The birefringence is compared in optical fibers with and without photosensitive inner cladding.

Investigations on birefringence effects in polymer optical fiber Bragg gratings

“…Like in silica fiber, the lateral writing process in (m)POF induces a small quantity of birefringence that combines with the intrinsic fiber birefringence and leads to polarization effects within the grating 23 . This small amount of birefringence causes the orthogonal polarization modes to experience different couplings through the grating 24 .…”

Analysis of birefringence and eigen-axes orientation resulting from the interplay between initial and form birefringence in UV-illuminated fiber

“…1). The refractive index change profile of the illuminated fiber is assumed to have an exponential decay across the photosensitive regions [1][2][3][4]. So, after exposure by a UV-beam incident at angle θ with respect to the X-axis, the index change at a point M(x M ,y M ) is given by:…”

“…Previous numerical analysis of photoinduced birefringence in UV-illuminated fibers did not take into account the birefringence of the pristine fiber [1][2][3]. It is well-known that, because of manufacturing imperfections, real optical fibers differ from the ideal cylindrical waveguide model and are characterized by a weak birefringence.…”

Measurement of photo-induced birefringence in germanosilicate fibers

“…Zhang et al measured photo-induced birefringence by using a fiber loop and its value can attain 10 −5 [13]. A significant improvement of the research in photo-induced birefringence was theoretically analysis by use of finite-element method [14,15].…”