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The quadratic electro-optic effect in the nonconjugated conductive polymer iodine-doped poly( β -pinene), measured at longer wavelengths including 1.55 μm, is reported. The field-induced birefringence technique was used. A modulation depth of 0.1% was observed in a 1 μm thick sample for an applied field of 1 V/μm at 1.55 μm. The corresponding Kerr coefficient obtained is 1.6×10 −10 m/V 2 . The Kerr coefficients measured at 790–810 nm are also very large. This exceptionally large (largest known) optical nonlinearity has been attributed to the subnanometer size metallic quantum dots formed in this polymer upon doping with iodine and the optimized film quality recently achieved.

Organic single-crystal films involving a combination of a molecular salt (DAST) and a laser dye (IR-125) have been grown on quartz substrates using the modified shear method. Polarized optical microscopy, polarization-dependent optical absorption, x-ray diffraction and electro-optic effect have been measured to characterize the film. The dipole axis of DAST is oriented close to parallel to the substrate. The IR-125 molecule appears to be oriented close to perpendicular to the dipole axis of DAST. The optical gap of the film is about 1.4 eV. The electro-optic coefficient ( r 11 ) as measured by the field-induced birefringence is ∼300 pm/V at 633 nm. Such films are promising for various photonic applications.

Thin films of 1,4-trans-polyisoprene have been prepared on various substrates from toluene solution and characterized using Fourier transform infrared (FTIR) spectroscopy, optical absorption spectroscopy and X-ray diffraction before and after doping with iodine. The optical absorption spectrum at low doping shows two peaks: one at 4.2 eV and the other at 3.2 eV. X-ray diffraction indicates an increase of (111) and (122) peak intensities upon doping. Quadratic electro-optic measurements have been made using field-induced birefringence. The Kerr coefficients as measured (3.5×10−10 m/V 2 at 633 nm and 2.5×10−10 m/V 2 at 1.55 μm) are exceptionally large, and they have been attributed to the subnanometer-size metallic domains formed upon doping and charge transfer.

We report the results of optical absorption, quadratic electro-optic and electroabsorption measurements in a novel nano-optical material based on the nonconjugated conductive polymer, poly(ethylenepyrrolediyl) derivative. Two peaks at about 310 and 420 nm have been observed in the optical absorption spectrum of the polymer at a low doping level of iodine. The Kerr constant as determined at 633 nm, which is close to resonance, is about 1.2×10−9 m/V 2 which is about 495 times that of nitrobenzene. This exceptionally large Kerr coefficient has been attributed to the special structure and quantum confinement of this electronic system within a subnanometer domain.