A simple structure of all circular-air-holes photonic crystal fiber for achieving high birefringence and low confinement loss

Abstract

We propose a simple structure of photonic crystal fibers (PCFs) with high birefringence and low confinement loss based on one rectangular centric ring of smaller circular air holes (CAHs) in the fiber core, and three rings of larger CAHs in the fiber cladding. This simple geometry (using all CAHs with two different air hole sizes) is capable of achieving a flexible control of the birefringence, B = 5.501 × 10−3, and ultra-low confinement loss, 7.30 × 10−5 dB/km, at an excitation wavelength of λ = 1550 nm. The birefringence value is ∼5.0 times greater than that obtained for conventional CAH PCF. This simple structure has the added advantage from the view point of easy fabrication, robustness, and cost. A full-vector finite element method combined with anisotropic perfectly matched layers was used to analyze the various fiber structures. We have analyzed four cases of CAH PCFs, focusing on the core asymmetry design as opposed to the conventional approach of CAHs or elliptical air holes on the cladding and core. The robustness against manufacturing inaccuracies of the proposed structure has also been further investigated in this work.

A highly birefringent photonic crystal fiber with compact cladding layers suitable for fiber optic gyroscope application

“…Due to seldom research works related to the high birefringent PCF for the application of FOG, the comparison table has been taken for more specific references which discuss the compactness of PCF with high birefringence. The proposed PCF has only circular air holes, whereas some other research works have also reported to show the impact of different types of air holes such as elliptical [45,46] and circular [18,47] to achieve high birefringence. There are number of fabrication techniques to fabricate PCF today, like sol gel casting [48], stack and draw process [49], drilling method [50], and extrusion method [51].…”

Design of an Ultrahigh Birefringence Photonic Crystal Fiber with Large Nonlinearity Using All Circular Air Holes for a Fiber-Optic Transmission System

“…Several such PCFs that attain the abovementioned properties using all circular air holes were the subject of many studies. For example, Chau et al designed a simple PCF structure using only circular air holes and obtained birefringence of about 5.501 × 10 −3 at 1550 nm [20]. Yang et al proposed a novel PCF with all circular air holes, with two enlarged air holes in the first ring of the cladding and three shrunken air holes in the core region.…”