Broadband laser polarization control with aligned carbon nanotubes

TL;DR

This paper presents a simple, broadband, low-cost polarization control device using aligned carbon nanotubes integrated into fiber lasers, achieving high extinction ratios and full polarization control at important telecom wavelengths.

Contribution

The work introduces the first application of aligned carbon nanotube devices for polarization control in fiber laser systems, demonstrating their effectiveness and broadband capabilities.

Findings

Achieved linearly-polarized output with ~12 dB extinction ratio.

Full polarization control via ACNT alignment in fiber lasers.

Demonstrated broadband polarization control at 1 and 1.5 μm wavelengths.

Abstract

We introduce a simple approach to fabricate aligned carbon nanotube (ACNT) device for broadband polarization control in fiber laser systems. The ACNT device was fabricated by pulling from as-fabricated vertically-aligned carbon nanotube arrays. Their anisotropic property is confirmed with optical and scanning electron microscopy, and with polarized Raman and absorption spectroscopy. The device was then integrated into fiber laser systems (at two technologically important wavelengths of 1 and 1.5 um) for polarization control. We obtained a linearly-polarized light output with the maximum extinction ratio of ~12 dB. The output polarization direction could be fully controlled by the ACNT alignment direction in both lasers. To the best of our knowledge, this is the first time that ACNT device is applied to polarization control in laser systems. Our results exhibit that the ACNT device is a simple, low-cost, and broadband polarizer to control laser polarization dynamics, for various photonic applications (such as material processing, polarization diversity detection in communications), where the linear polarization control is necessary.