Mach-Zehnder Interferometers Based on Long Period Fiber Grating Coated With Titanium Dioxide for Refractive Index Sensing

• Type: Article in International Scientific Journal
• Date: 2019

Authors

Soares Guedes Vasconcelos, HCASG (Author) Other; de Almeida, JMMM (Author) FCUP; Teixeira Saraiva, CMT (Author) Other; Jorge, PAS (Author) FCUP; Costa Coelho, LCC (Author) FCUP

Journal

Title: Journal of Lightwave Technology

Vol. 37

Pages: 4584-4589

ISSN: 0733-8724

Publisher: Optical Society of America

Indexing

ISI Web of Knowledge - 12 Citations

Scopus - 12 Citations

Other information

Authenticus ID: P-00Q-SFV

DOI: 10.1109/jlt.2019.2912829

Abstract (EN): The wavelength sensitivity and spectral resolution of Mach-Zehnder fiber interferometers obtained through a combination of two identical uncoated and titanium dioxide (TiO2) coated long period fiber gratings (LPFGs) is presented and compared with single LPFGs-based refractometric sensors. A set of LPFGs were fabricated in single mode fiber with the resonance band having an amplitude of 3 dB in order to split in half the optical power between the core and the specific cladding modes. The separation between the pair of LPFG written in the fiber was varied between 1 and 3 cm and the thickness of the TiO2 coating around the fiber ranged from 20 to 40 nm. A wavelength shift sensitivity of 216 nm/refractive index units (RIU) was achieved for the device with 3 cm and a 30-nm thick TiO2 coating, which presented a spectral resolution of 1.1 x 10(-4 )Rill Despite the lower wavelength shift sensitivity of 142 nm/RIU, attained for a 2-cm long device and 30-nm thick TiO2 coating, a spectral resolution of 1.8 x 10(-5) RIU was measured, which is one order of magnitude lower than a single LPFG.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6