Intermodal Brillouin scattering in solid-core photonic crystal fibers

Paulo F Jarschel,Julian L Pita,Erick Lamilla,Andres Gil-Molina,Yovanny A V Espinel,Paulo Dainese,Ivan Aldaya,Gustavo S Wiederhecker

doi:10.1063/5.0040580

Paulo F Jarschel, Julian L Pita + Show 6 more

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https://doi.org/10.1063/5.0040580

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Journal: APL Photonics	Publication Date: Mar 1, 2021
Citations: 4	License type: cc-by

Affiliation: Universidade Estadual de Campinas

Abstract

We investigate intermodal forward Brillouin scattering in a solid-core photonic crystal fiber (PCF), demonstrating efficient power conversion between the HE11 and HE21 modes, with a maximum gain coefficient of 21.4 W−1 km−1. By exploring mechanical modes of different symmetries, we observe both polarization-dependent and polarization-independent intermodal Brillouin interaction. Finally, we discuss the role of squeeze film air damping and leakage mechanisms, ultimately critical to the engineering of PCF structures with enhanced interaction between high-order optical modes through flexural mechanical modes.

Highlights

Applications exploring optical waveguides and cavities supporting multiple spatial modes have greatly expanded in recent years
Albeit previously considered as an impairment for optical communications, multimode systems regained attention as the basis of mode division multiplexing (MDM)1,2 and can substantially enhance the capabilities in many other applications such as sensing,3–6 particle manipulation,7–9 and nonlinear optical devices, for example, in frequency comb generation in multimode ring resonators10 and non-reciprocal devices based on Brillouin scattering in multimode waveguides
Using the lock-in amplifier (LIA) detection method, we first obtained the intermodal Brillouin spectrum shown in Fig. 3 for parallel and orthogonal pump-signal polarizations

Summary

Introduction

Applications exploring optical waveguides and cavities supporting multiple spatial modes have greatly expanded in recent years. Albeit previously considered as an impairment for optical communications, multimode systems regained attention as the basis of mode division multiplexing (MDM) and can substantially enhance the capabilities in many other applications such as sensing, particle manipulation, and nonlinear optical devices, for example, in frequency comb generation in multimode ring resonators and non-reciprocal devices based on Brillouin scattering in multimode waveguides.. Nonlinear optical effects offer a path to enable and control intermodal interactions, for example, using Kerr-induced long period gratings to perform all-optical mode conversion.. Besides enabling direct power exchange between different spatial modes, SBS can be explored as a mode-selective isolator or modeselective variable optical attenuator (VOA) and has recently been explored as the basis for non-reciprocal devices. Nonlinear optical effects offer a path to enable and control intermodal interactions, for example, using Kerr-induced long period gratings to perform all-optical mode conversion. Stimulated Brillouin scattering (SBS) is another nonlinear mechanism that can be explored for intermodal interaction, with unique properties. Besides enabling direct power exchange between different spatial modes, SBS can be explored as a mode-selective isolator or modeselective variable optical attenuator (VOA) and has recently been explored as the basis for non-reciprocal devices.

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