Optoelectronic systems switches

Scheme 6 Examples of optoelectronic molecular switching systems based on DHA/VHF-photochromism.

The area of molecular nonlinear optics has been rejuvenated by efforts to investigate three-dimensional multipolar systems, functionalized polymers as optoelectronic materials, near infrared optical parametric oscillators and related aspects.71 There have been some advances in chromophore design for second-order nonlinear optical materials 72 these include onedimensional CT molecules, octopolar compounds and organometallics. Some of the polydiacetylenes and poly(/>-phenylenevinylene)s appear to possess the required properties for use as third-order nonlinear optical materials for photonic switching.73... 

Substantial progress has been accomplished in the fabrication of molecular and biomolecular optoelectronic devices. Light-activated molecular and bio-molecular systems have been integrated with electronic transducers, and the optical switching of the systems has been electronically transduced to the macroscopic environment. In particular, the photonic switching of an electron-transfer cascade has allowed the amplified electronic transduction of an input... 

The third approach to the assembly of molecular optoelectronic switches is shown in Fig. 26, and involves the association of a chemically functionalized surface with a photoisomerizable guest. In configuration A of the molecular component, no affinity interactions with the modified surface exist, and the system is in a mute state. Photoisomerization of the substrate to state CB activates the affinity binding of the molecular component to the surface - a process that can be electronically transduced (e.g. to give an amperometric impedance or piezoelectric signal). 

In today s high-tech society, information is increasingly transported through optical networks (optical fibres and optoelectronic switches) due to the recent developments in telecommunications. Vast amounts of data can be encoded and transported over large distances. However, it is becoming apparent that the use of electrical inputs to send optical signals cannot sustain the projected amount of information that will need to be transferred in the future (of the order of terabits-per-second). Therefore, to efficiently transport information via optical networks, a fully optical system is needed. 

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