Open AccessUltranarrow filter based on Fano resonance in a single cylindrical microresonator for single-longitudinal-mode fiber lasers
Author(s) -
Haotian Wang,
Rui Xu,
Jianing Zhang,
Wei Zhou,
Deyuan Shen
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.022717
Subject(s) - laser linewidth , optics , fiber laser , materials science , lasing threshold , laser , fano resonance , single mode optical fiber , longitudinal mode , optoelectronics , physics , plasmon
A novel single-longitudinal-mode (SLM) fiber laser with a single cylindrical microresonator (CMR) as the filter is proposed. The CMR has a nanoscale variation in radius, in which high-Q localized modes interfere with continuum radiative modes, generating a peak-like transmission spectrum based on the Fano resonance effect. The peak linewidth is sufficiently small to select only one SLM oscillation in a fiber cavity. In an Er-doped fiber laser coupled with the CMR, we achieve a stable SLM laser operation by optimizing the coupling location of the tapered fiber. Stable lasing at 1568 nm with a 3-dB linewidth of ∼15 kHz is obtained. The laser slope efficiency reduction introduced by the CMR for SLM lasing is limited to 1.4%. This scheme can be a competitive approach for the development of compact, highly efficient, and cost-effective SLM fiber lasers.