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Chapter I Brief Introduction...
fashion than that can be done in electronics. Another advantage is that light
being made up of uncharged photos, which do not interact with one another
as readily as electrons do. The role of NLO materials have becomes
extremely important. Such materials can change the color of light and
modulate its properties. Several optical computers require efficient nonlinear
optical materials for their operations. Several organic materials have been
explored for their use in optical devices, having high nonlinearities, flexibility of
molecular design and damage resistance to optical radiation. A novel photo-
deposition process for film on to quartz or glass surface has been carried out
in NASA which enabled polydiacetylene film deposition having large
nonlinearities and fast response time less than 120 fs (1fs=10 -15 s). The optical
AND and NAND gates have been demonstrated [111].
Mardar [27], in his well known article on Organic NLO materials.
“Where we have been and where we are going”, has given details of future
developments. It is expected that the electro-optic coefficient value of 500
pm/V would be achieved in poled polymers, which may enable their use for
various applications such as, efficient terahertz frequency generation
facilitating image process for medical and security purpose. It is expected that
all optical signal processing will be possible based on third-order NLO
materials. The rapid development of two-photon micro-fabrication will help to
push the limits of achievable resolution below 100 nm. The application of
organic NLO materials for biomedical application including imaging, sensing,
treatment and tissue engineering will be envisaged. The combination of
efficient organic NLO materials with nano-structured metal clusters will
provide dramatically enhanced NLO effects through surface plasmons.
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