Black phosphorus: a two-dimension saturable absorption material for mid-infrared Q-switched and mode-locked fiber lasers

TLDR

Black phosphorus is a novel two‑dimensional material with strong light‑matter interaction and a tunable band‑gap, making it ideal for mid‑infrared saturable absorption. The study aims to fabricate black phosphorus via liquid‑phase exfoliation and employ it as a saturable absorber in mid‑infrared fiber lasers. The authors produced BP by a simple liquid‑phase exfoliation process and incorporated it into rare‑earth‑doped fluoride fiber lasers. Using the BP saturable absorber, they achieved Q‑switching with 4.93 µJ pulse energy and mode‑locking with 8.6 ps pulse duration at ~2970 nm, the longest wavelength reported for BP‑based fiber lasers.

Abstract

Abstract Black phosphorus (BP) as a novel class of two-dimension (2D) materials has recently attracted enormous attention as a result of its unique physical and chemical features. The remarkably strong light-matter interaction and tunable direct band-gap at a wide range make it an ideal candidate especially in the mid-infrared wavelength region as the saturable absorber (SA). In this paper, the simple and effective liquid phase exfoliation (LPE) method was used to fabricate BP. By introducing the same BP SA into two specifically designed rare earth ions doped fluoride fiber lasers at mid-infrared wavebands, Q-switching with the pulse energy of 4.93 μJ and mode-locking with the pulse duration of 8.6 ps were obtained, respectively. The operation wavelength of ~2970 nm for generated pulse is the reported longest wavelength for BP SA based fiber lasers.