Comb mode converters based on sampled helical gratings

TL;DR

This paper introduces sampled helical gratings that enable flexible mode conversion and wavelength filtering for fiber-guided orbital angular momentum modes, advancing hybrid multiplexing technologies.

Contribution

It presents a novel sampled reflection helical grating design that combines mode conversion and wavelength filtering for fiber OAM modes.

Findings

Realizes generation and conversion of OAM modes with comb spectra

Enables simultaneous wavelength filtering and mode conversion

Potential application in hybrid wavelength and mode division multiplexing

Abstract

Helical gratings (HGs) have an achievement of flexible mode conversion for fibre guided orbital angular momentum (OAM) modes. Sampled reflection HGs can realise the generation and conversion of OAM mode with comb spectra. They can be used to simultaneously filter wavelengths and convert modes, and thus may be applied to the hybrid multiplexing technology with wavelength division multiplexing and mode division multiplexing.