External modulators based on LiNbO3 Mach-Zehnder devices and
electro-absorption modulators are standard components in long-haul
and local area fiber optic networks. However, the high refractive
index of LiNbO3 as compared to the glass optical fiber, the
processing of the crystal into a rectangular waveguide (W.G), and
the difficulties of coupling between rectangular W.G and cylindrical
optical fiber are critical factors in manufacturing of these types of
modulators and results in a very high price.
As an alternative to the standard modulators, our on-fiber modulator
is based on coating regular silica fiber core with an electro-optic
material which is easy to process and which have refractive indices
compatible to the glass fiber. An excellent extinction ratio is possible
with this new innovative modulator, which is better than the LiNbO3
Mach-Zehnder and electro-absorption type optical modulators.
