Low-loss deposition of solgel-derived silica films on tapered fibers.
Films of porous silica are deposited on the uniform waists of tapered fibers in minutes by a modified solgel dip coating method, inducing less than 0.2 dB of loss. The coated tapers are an ideal platform for realizing all-fiber devices that exploit evanescent-field interactions with the deposited porous film. As an example we demonstrate structural long-period gratings in which a periodic index variation in the film arises from the porosity variation produced by spatially varying exposure of the waist to a scanned CO2 laser beam. The long period grating is insensitive to temperature up to 800 degrees C.
Kakarantzas
G
G
Optoelectronics Group, Department of Physics, University of Bath, Claverton Down, Bath, BA2 7AY, UK. gkakaran@mail.ntua.gr
Leon-Saval
S G
SG
Birks
T A
TA
Russell
P St J
PS