Open AccessUltrasensitive optical sensing in aqueous solution based on microfiber modal interferometer
Author(s) -
Jing Wang,
Yipeng Liao,
Shanshan Wang,
Xin Wang
Publication year - 2018
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.26.024843
Subject(s) - microfiber , optics , interferometry , materials science , wavelength , refractive index , sensitivity (control systems) , absorption (acoustics) , fabrication , optoelectronics , physics , medicine , alternative medicine , pathology , electronic engineering , composite material , engineering
In this paper, an ultrahigh sensitivity sensing in aqueous solution for microfiber modal interferometer (MMI) is realized. The group refractive index (RI) difference between HE 11 and HE 12 mode will come down to 0 at a certain wavelength, resulting in ultrahigh sensitivity near this wavelength. MMI with different diameters have their individual ultrasensitive wavelength band, which indicates the broad range of optional probing wavelength and more liberal diameter condition on fiber fabrication. In the experimentation, infrared absorption band in water around 1360-1600nm is easy to keep away by adjusting the microfiber diameter. As a result, an ultrahigh sensitivity of 14.95 pm/ppm is realized for sodium nitrate at 1320nm, whose equivalent sensitivity is about 1.26 × 10 5 -nm/RIU for RI, which is much higher than most of the existing naked sensors with magnitude of 10 2 -10 4 nm/RIU.