A new type of oxygen sensor is proposed with an ion-sensitive film of
V2O5 on an optical waveguide surface and is characterized using prism-
film coupling. Upon exposure to excess oxygen in ambient air, the ligh
t (lambda = 632.8 nm) transmission through the guide alters due to the
change in the refractive index of the film, changing the effective in
dex of the guide. The excess O-2 concentration varies from 50 ppm to f
ew per cent (5%). The influence of the cladding thickness (150-490 nm)
and the length (2-6 mm) on the sensor performance are studied. The in
crease in cladding length enhances the static sensitivity, while the i
ncrease in the thickness causes a reduction in the static sensitivity,
unaffecting the incremental sensitivity. The performance is identical
with static and incremental methods, The response and recovery times
are found to be 4-6 and 8s, respectively. An air ambient sintering of
the films gives practically a linear response compared to nonsintered
films. The sensors are tested for other gases, namely H-2 and H2O, doe
s not show any response except O-2.