Information Technology Reference
In-Depth Information
Fig. 3.45 Chiropticene molecule
Fig. 3.46 Scheme of the intramolecular transitions in the chiropticene molecule
of this molecule is schematically shown in Fig.
3.45
(the exact structure is a
commercial secret of the corporation). This optically active molecule was not
discovered, but rather invented. Its two optical isomers—two stable states of the
molecule—have oppositely directed dipole moments, making it possible to use
electrical signals for switching. The barrier between the conformations is large
enough to eliminate accidental switching caused by random fluctuations, impeding
at the same time the switching by an electrical signal. For this reason, a photosen-
sitive group is introduced into the structure of the molecule, and the characteristics
of the molecular system are chosen such that the energy barrier between the
conformations of the molecule in its excited state would be significantly smaller
than in the ground state (Fig.
3.46
). Thus, the molecule gets switched by a
simultaneous effect of light radiation and electric field. The absorption band of
the photosensitive group, whose structure is a commercial secret, coincides with the
wavelength of a common laser. Under this scheme the switching time is in the
femtosecond range, making chiropticene a fast switching element.
