Liquid crystals waveguide switching technology
24 January 2012 - 26 January 2012
Austria
Either for signal switching in optical communication networks or fiber sensor
networks the optical path connection needs to be dynamically controlled.
Optical switches and routers are devices designed to execute such essential
control functions.
The market demand on current optical switching device technologies
for high reliability and stability of switching, for switching between many inputand
output-channels as well as for providing low optical loss, low cross-talk and
short switching times.
Optical switches with no moving parts, such as the liquid crystal based devices,
warrant high operation stability and reliability. This is one of the reasons to
decide for Fraunhofer IPMS’s liquid crystal optical switching devices. Yet, what
makes this technology truly attractive is the use of isotropic liquid crystals
which, through the underlying quadratic electro-optic Kerr effect, render the
device remarkable properties: sub-micro-second switching times and excellent
transparency over a broad spectral range from 400 nm to 1600 nm, at a still
reasonable operation voltage. All the more, due to their straightforward design,
these devices are easily integrable and manufacturable by means of high
precision, planar silicon wafer technology.
The Fraunhofer IPMS’s optical switching device, presented in the figure, is made
on two bonded silicon wafers – forming the base and the top parts of the chip
– each including structured electrodes stripes. The wafers enclose in between
an isotropic liquid crystal layer. An electric field applied between selected
electrodes from both parts of the chip and across the liquid crystal layer causes
a local change of the refractive index on corresponding regions inside this layer.
Light waves can be guided on the paths, thus ‘activated’, at an optical loss of
better than 2 dB/cm.
The technology based on such ‘active’ optical waveguides permits, just by
structuring suitable electrodes on the chip, the fabrication of optical switches
with multiple inputs and outputs at either single- or multi-mode operation.
Fraunhofer IPMS’s optical switching device technology offers hence remarkable
advantages in terms of switching stability and reliability, since no moving
parts are involved, then device design flexibility and scalability are warranted
as well as simple wafer level fabrication. The requirements for low cost and
high volume manufacturing are therefore met. Furthermore, by using this
technology, the range of functions implemented on a device can be extended
to include interconnection, optical attenuation and modulation. These devices
can be tailored to meet the specific needs of optical networks, remote sensing
and laser technology applications.
networks the optical path connection needs to be dynamically controlled.
Optical switches and routers are devices designed to execute such essential
control functions.
The market demand on current optical switching device technologies
for high reliability and stability of switching, for switching between many inputand
output-channels as well as for providing low optical loss, low cross-talk and
short switching times.
Optical switches with no moving parts, such as the liquid crystal based devices,
warrant high operation stability and reliability. This is one of the reasons to
decide for Fraunhofer IPMS’s liquid crystal optical switching devices. Yet, what
makes this technology truly attractive is the use of isotropic liquid crystals
which, through the underlying quadratic electro-optic Kerr effect, render the
device remarkable properties: sub-micro-second switching times and excellent
transparency over a broad spectral range from 400 nm to 1600 nm, at a still
reasonable operation voltage. All the more, due to their straightforward design,
these devices are easily integrable and manufacturable by means of high
precision, planar silicon wafer technology.
The Fraunhofer IPMS’s optical switching device, presented in the figure, is made
on two bonded silicon wafers – forming the base and the top parts of the chip
– each including structured electrodes stripes. The wafers enclose in between
an isotropic liquid crystal layer. An electric field applied between selected
electrodes from both parts of the chip and across the liquid crystal layer causes
a local change of the refractive index on corresponding regions inside this layer.
Light waves can be guided on the paths, thus ‘activated’, at an optical loss of
better than 2 dB/cm.
The technology based on such ‘active’ optical waveguides permits, just by
structuring suitable electrodes on the chip, the fabrication of optical switches
with multiple inputs and outputs at either single- or multi-mode operation.
Fraunhofer IPMS’s optical switching device technology offers hence remarkable
advantages in terms of switching stability and reliability, since no moving
parts are involved, then device design flexibility and scalability are warranted
as well as simple wafer level fabrication. The requirements for low cost and
high volume manufacturing are therefore met. Furthermore, by using this
technology, the range of functions implemented on a device can be extended
to include interconnection, optical attenuation and modulation. These devices
can be tailored to meet the specific needs of optical networks, remote sensing
and laser technology applications.