By Topic

Photodarkening and photobleaching in fiber optic Bragg gratings

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
Askins, C.G. ; Div. of Opt. Sci., Naval Res. Lab., Washington, DC, USA ; Putnam, M.A.

A photobleaching effect is reported which reduces the broadband losses induced by the single-pulse writing of fiber Bragg gratings (FBGs). A primary application of the optical FBG reflector is as arrays of wavelength-encoded sensing elements for detecting mechanical strain. Instrumentation is being developed to interrogate >100 point sensors along a single fiber with FBGs and detectors operating in the 790-820 nm band. In this paper, we describe broadband absorptions induced by writing single-pulse FBGs which would impose a 10 dB power penalty with as few as 40 serialized FBGs. We have reduced these photo-induced losses more than seven-fold (measured near 800 nm) using a photobleaching process which minimally affects the FBG's reflectivities. After treatment, optical losses are sufficiently low to allow the interrogation of hundreds of FBGs along a single fiber. Photodarkening and photobleaching are measured in gratings prepared by single laser pulses, and by multiple pulses with and without hydrogen loading. Parasitic loss following photobleaching is lower for single-pulse FBGs operated near 800 nm than for FBGs written with multiple pulses in hydrogen loaded fibers and operated near 1300 nm

Published in:

Lightwave Technology, Journal of  (Volume:15 ,  Issue: 8 )