Abstract
The authors have successfully fabricated planar micro-optical switch device exploiting the transmitting semiconductor (on) to the reflecting metallic (off) phase transition of thermochromic
W
(
1.4
at.
%
)
-doped
V
O
2
smart coatings and driven by an external voltage. The starting W-doped
V
O
2
-coated
Al
2
O
3
exhibited infrared transmittance switching about 45%. After the microfabrication, the temperature dependence of electrical resistance of the micro-optical switch showed clearly its well-known semiconductor-to-metallic phase transition at a transition temperature of
36
°
C
. A reversible transmittance switching (on/off) as high as
28
dB
was achieved with this device at
λ
=
1.55
μ
m
. In addition, the transmittance switching modulation of the device was demonstrated at
1.55
μ
m
by switching the micro-optical switch simultaneously with dc and ac voltages.