  Photonic crystals can integrate plasmonic materials such as indium tin oxide
(ITO) in their structure. Exploiting ITO plasmonic properties it is possible to
tune the photonic band gap of the photonic crystal upon the application of an
external stimuli. In this work, we have fabricated a one-dimensional multilayer
photonic crystal via radiofrequency sputtering and we have triggered its
optical response with ultrafast pump-probe spectroscopy. Upon photoexcitation
we observe a change in the refractive index of indium tin oxide. Such effect
has been used to create a photonic crystal that change its photonic bandgap in
an ultrafast time scale. All optical modulation in the visible region, that can
be tuned by designing the photonic crystal, has been demonstrated.
