Open AccessOptical fiber laser refractometer based on an open microcavity Mach-Zehnder interferometer with an ultra-low detection limit
Author(s) -
Panpan Niu,
Junfeng Jiang,
Shuang Wang,
Kun Liu,
Zhe Ma,
Yongning Zhang,
Wenjie Chen
Publication year - 2020
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.401813
Subject(s) - optics , materials science , refractometer , interferometry , laser , mach–zehnder interferometer , graded index fiber , optical fiber , single mode optical fiber , refractive index , optoelectronics , fiber optic sensor , physics
A fiber laser refractometer based on an open microcavity Mach-Zehnder interferometer (OMZI) is proposed. The open microcavity is constructed by embedding a segment single-mode fiber (SMF) into two multi-mode fiber (MMF) joints with lateral offset for liquid sample, which has the advantages of micro sensing element and easy fabrication. The transmission characteristics of the MMF-assisted OMZI are investigated by simulating and manufacturing the OMZIs with different microcavity lengths and offset distances. By inserting the MMF-assisted OMZI into the erbium-doped fiber ring laser (FRL) cavity, the lasing wavelength can be used to detect the refractive index (RI) change of the medium in the microcavity. Experimental results show a high sensitivity of -2953.444 nm/RIU within the measurement range of 1.33302∼1.33402. More importantly, with the combination of OMZI and FRL, the proposed fiber laser refractometer realizes ultra-low detection limit (DL) and high-quality factor Q, which are two orders of magnitude better than that of previous reports.