Engineering Adiabaticity for Efficient Design of Photonic Lanterns

Abstract

We present a comprehensive systematic framework for optimizing adiabaticity in photonic lanterns. The framework considers the effects of both the cross-sectional and longitudinal device parameters on adiabaticity. Photonic lanterns are adiabatic photonic devices and are therefore known to have large device lengths. A Shortcuts-to-adiabaticity (STA) protocol is employed to optimize the adiabatic taper profile in all-fibre photonic lanterns. The method tailors adiabatic propagation of light in the system by appropriately correcting the local slope of the taper profile. A quantifiable measure of adiabaticity is established, based on the adiabaticity criterion. This measure relates inversely to the device length and is a useful parameter in taper optimization. We apply the protocol to reported photonic lantern devices to obtain optimal adiabatic taper profiles having shorter device lengths. The optimized taper profile refers to that taper profile which corresponds to the minimum local intermodal coupling at every point along the quasi-adiabatic transition for a given device length. While optimizing the adiabatic transition by minimizing intermodal coupling is the basic aim of this work, length optimization is an extremely useful by-product. This procedure can be used to either reduce the device length or to reduce the mode-coupling losses or both. This study analyses reported three and six-core mode selective photonic lanterns as examples. We also discuss ways to make the optimum profiles practically realizable.

Advancements in Optical Communication Research: A Review of India's Progress

“…In the area of fiber-optics, many research groups work on the design of optical fibers for various applications and also fiberbased components such as fiber couplers/splitter, fiber-coupled sources. All fiber based component such as fiber couplers, photonic lanterns, wavelength-division multiplexers are developed in-house at IIT Delhi [22], [23]. Specialty fibers such as multi-core fibers, few mode fibers are explored for their application in space division multiplexing in our lab -optical communication engineering and networking at IIT Madras.…”