Fresnel-Reflection-Free Self-Aligning Nanospike Interface between a Step-Index Fiber and a Hollow-Core Photonic-Crystal-Fiber Gas Cell

Abstract

Splicing optical fibers for good transmission is important, and can be tricky. This study presents a photonic device for launching light from a single-mode fiber to a hollow-core photonic-crystal fiber, based on inserting a glass-fiber ``nanospike'' into the hollow core. Optomechanics and the adiabatic evolution of the optical mode are exploited to achieve self-aligned, efficient light coupling in a compact, ready-to-use integrated device. This hardware would naturally see application in telecommunications, light-gas interaction and spectroscopy, and nonlinear and quantum optics.