Broadband and low-loss mode scramblers using CO2-laser inscribed long-period gratings

Yunhe Zhao; Haoshuo Chen; Nicolas K Fontaine; Jiaxiong Li; Roland Ryf; Yunqi Liu

doi:10.1364/OL.43.002868

Broadband and low-loss mode scramblers using CO₂-laser inscribed long-period gratings

Opt Lett. 2018 Jun 15;43(12):2868-2871. doi: 10.1364/OL.43.002868.

Authors

Yunhe Zhao, Haoshuo Chen, Nicolas K Fontaine, Jiaxiong Li, Roland Ryf, Yunqi Liu

PMID: 29905710
DOI: 10.1364/OL.43.002868

Abstract

We demonstrate broadband and low-loss three-mode and six-mode scramblers employing CO₂-laser inscribed long-period gratings (LPGs) for space-division multiplexing. Step-index (SI) few-mode fibers are used to avoid mode coupling to the cladding modes. We characterize the mode scramblers using a swept-wavelength interferometer. Mode-dependent loss (MDL) and modal transfer matrices over the C+L band are presented. Demonstrated LPGs with negligible MDL and low insertion loss contributed to high-performance CO₂-laser inscription. The total MDLs induced by the SI fiber with LPGs in three-mode and six-mode scramblers are measured to be 2 and 4 dB, respectively.