Abstract
An in-line chemical gas sensor was proposed and experimentally demonstrated using a new C-type fiber and a Ge-doped ring defect photonic crystal fiber (PCF). The C-type fiber segment served as a compact gas inlet/outlet directly spliced to PCF, which overcame previous limitations in packaging and dynamic responses. C-type fiber was prepared by optimizing drawing process for a silica tube with an open slot. Splicing conditions for SMF/C-type fiber and PCF/C-type fiber were experimentally established to provide an all-fiber sensor unit. To enhance the sensitivity and light coupling efficiency we used a special PCF with Ge-doped ring defect to further enhance the sensitivity and gas flow rate. Sensing capability of the proposed sensor was investigated experimentally by detecting acetylene absorption lines.
Highlights
In recent years, micro-structured optical fibers, especially photonic crystal fibers (PCFs) [1], have attracted considerable interests for sensing applications due to the fact that micro-holes in PCFs can provide a strong interaction between the guided light with gases or liquids filled there within [2,3,4,5,6]
Light from an Er-doped amplified spontaneous emission (ASE) source passed through the fiber optic sensing unit and measurements were done using an optical spectrum analyzer (OSA) and a power meter
Using high accuracy mass flow controllers (MFC), we could vary the partial pressure of acetylene and nitrogen gases
Summary
Micro-structured optical fibers, especially photonic crystal fibers (PCFs) [1], have attracted considerable interests for sensing applications due to the fact that micro-holes in PCFs can provide a strong interaction between the guided light with gases or liquids filled there within [2,3,4,5,6]. While the butt coupling method is the most general approach [10], other methods such as using periodic openings [11], drilling holes in PCF with a femtosecond laser [12] and drawing fiber with a laterally slotted preform [13] have been proposed for the gas inlet/outlet. Those methods still have raised significant difficulties: requirement of elaborated alignment processes for each measurement, broken symmetry in the periodic structure of the PCF, too small holes for efficient measurand entry, as well as sophisticated fabrication processes. The dynamic response of the sensor was quantified in detail
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
