Abstract

All-optical fiber sensors based on ultracompact fiber inline Mach-Zehnder interferometer (MZI) are fabricated by side-ablating a Ushape microcavity in a single-mode optical fiber with the fiber core partially removed using femtosecond (fs) laser pulses, in which the two light paths are accordingly formed in the remaining D-type fiber core and the U-shape microcavity. Beam propagation method (BPM) analysis is utilized to illustrate the dependences of good transmission spectra on parameters including the ablation depth, ablation length and the refractive index of Ushape microcavity, which gives some guidelines to optimize parameters for fs laser micromachining and predicts RI (refractive index) sensitivities within given RI ranges. the modeling results of ultrahigh RI sensitivities for gases and solutions are-3243-75 ± 0.65nm/RIU (refractive index unit) and-10789.29 ± 18.91nm/RIU, respectively. in RI testing experiments, the sensor exhibits ultrahigh RI sensitivities of-3754.79 ± 44.24nm/RIU with refractive indices ranging from 1.0001143 to 1.0002187 by testing different mixture ratios of N2 and He gases, and-12162.01 ± 173.92nm/RIU with refractive indices ranging from 1.3330 to 1.33801 by testing different concentrations of sucrose solutions, which is essentially in agreement with the modeling results. © 2011 Optical Society of America.

Department(s)

Mechanical and Aerospace Engineering

Second Department

Electrical and Computer Engineering

International Standard Serial Number (ISSN)

1094-4087

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2024 Optica Publishing Group, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

29 Aug 2011

Share

 
COinS