Tailoring modal properties of inhibited-coupling guiding fibers by cladding modification

TL;DR

This paper demonstrates how modifying the cladding structure of inhibited-coupling guiding fibers can tailor their modal properties, enabling control over mode propagation, polarization, and intensity profiles for advanced optical applications.

Contribution

It introduces a method to tailor modal properties of hollow-core fibers through cladding modifications, influencing mode hierarchy and polarization characteristics.

Findings

Alteration of cladding affects mode loss hierarchy.

Cladding modifications enable propagation of higher order modes.

Fibers can act as mode shapers for intensity and polarization.

Abstract

Understanding cladding properties is crucial for designing microstructured optical fibers. This is particularly acute for Inhibited-Coupling guiding fibers because of the reliance of their core guidance on the core and cladding mode-field overlap integral. Consequently, careful planning of the fiber cladding parameters allows obtaining fibers with optimized characteristics such as low loss and broad transmission bandwidth. In this manuscript, we report on how one can tailor the modal properties of hollow-core photonic crystal fibers by adequately modifying the fiber cladding. We show that the alteration of the position of the unity-tubes in the cladding of tubular fibers can alter the loss hierarchy of the modes in these fibers, and exhibit salient polarization propriety. In this context, we present two fibers with different cladding structures which favor propagation of higher order core modes - namely LP11 and LP21 modes. Additionally, we provide discussions on mode transformations in these fibers and show that one can obtain uncommon intensity and polarization profiles at the fiber output. This allows the fiber to act as a mode intensity and polarization shaper. We envisage this novel concept can be useful for a variety of applications such as hollow core fiber based atom optics, atom-surface physics, sensing and nonlinear optics.