Fabrication of Long Period Gratings by Periodically Removing the Coating of Cladding-Etched Single Mode Optical Fiber Towards Optical Fiber Sensor Development

Joaquin Ascorbe; Jesus M Corres; Ignacio Del Villar; Ignacio R Matias

doi:10.3390/s18061866

Fabrication of Long Period Gratings by Periodically Removing the Coating of Cladding-Etched Single Mode Optical Fiber Towards Optical Fiber Sensor Development

Sensors (Basel). 2018 Jun 7;18(6):1866. doi: 10.3390/s18061866.

Authors

Joaquin Ascorbe¹, Jesus M Corres^{2

3}, Ignacio Del Villar^{4

5}, Ignacio R Matias^{6

7}

Affiliations

¹ Department of Electrical, Electronic and Communication Engineering, Public University of Navarra, 31006 Pamplona, Spain. joaquin.ascorbe@unavarra.es.
² Department of Electrical, Electronic and Communication Engineering, Public University of Navarra, 31006 Pamplona, Spain. jmcorres@unavarra.es.
³ Institute of Smart Cities, Public University of Navarra, 31006 Pamplona, Spain. jmcorres@unavarra.es.
⁴ Department of Electrical, Electronic and Communication Engineering, Public University of Navarra, 31006 Pamplona, Spain. ignacio.delvillar@unavarra.es.
⁵ Institute of Smart Cities, Public University of Navarra, 31006 Pamplona, Spain. ignacio.delvillar@unavarra.es.
⁶ Department of Electrical, Electronic and Communication Engineering, Public University of Navarra, 31006 Pamplona, Spain. natxo@unavarra.es.
⁷ Institute of Smart Cities, Public University of Navarra, 31006 Pamplona, Spain. natxo@unavarra.es.

Abstract

Here, we present a novel method to fabricate long period gratings using standard single mode optical fibers (SMF). These optical devices were fabricated in a three-step process, which consisted of etching the SMF, then coating it with a thin-film and, the final step, which involved removing sections of the coating periodically by laser ablation. Tin dioxide was chosen as the material for this study and it was sputtered using a pulsed DC sputtering system. Theoretical simulations were performed in order to select the appropriate parameters for the experiments. The responses of two different devices to different external refractive indices was studied, and the maximum sensitivity obtained was 6430 nm/RIU for external refractive indices ranging from 1.37 to 1.39.

Keywords: laser ablation; long period fiber gratings; micromachined; optical fiber sensors; refractometer; thin-film coatings.