Infrared Photorefractive Polymers and Their Applications for Imaging

Abstract

Photorefractive polymers with high diffraction efficiency in the visible and near-infrared regions of the electromagnetic spectrum have been developed. These polymers, which have a large dynamic range because of their high orientational birefringence, incorporate a dye designed to have a large dipole moment and a high linear polarizability anisotropy. Such polymers have enabled demonstrations of imaging through scattering media, using a holographic time-gating technique at a wavelength that is compatible with the transparency of biological tissues and with the emission of low-cost semiconductor laser diodes.

Photophysical and Redox NIR‐Sensitivity Enhancement in Photorefractive Polymer Composites

“…[29] The latter were about twice as sensitive as the best PVK/ TNFM-based systems. [30,31] We point out that a true comparison is difficult due to differences in the experimental conditions employed by the different groups, such as device thickness, operating wavelength, and electric field strength.…”

Transillumination imaging through scattering media by use of photorefractive polymers

“…12 Recently we designed a PR polymer that exhibits high performance from 700 to 900 nm, 13 which is desirable for medical imaging because this region of transparency is one of the best for biological tissue and is covered by commercially available Ti:sapphire lasers and by efficient and inexpensive laser diodes. The polymer used was a composite of the dye 2, N , N -dihexylamino-7-dicyanomethylidenyl-3, 4, 5, 6, 10-pentahydronaphthalene (25 wt.…”

Effect of Cyanine Dyes on Photoelectric, Nonlinear Optical and Photorefractive Properties of Composites Based on Carbon Nanotubes

“…For the purpose of use in biomedical studies, polymer composites possessing PR sensitivity at 830 nm, in region of action of a titanium-sapphire laser, were synthesized. [21] The transparency of tissues increases with an increase in the wavelength of electronic absorption, and InGaAs/GaAs multiple quantum well devices sensitive to 1064 nm were proposed as more promising for biomedical imaging. [22] These systems are costly and have restricted photorefractive characteristics; thus, the design of inexpensive polymer composites with high photorefractive properties that exhibit the photorefractive sensitivity at 1064 nm and longer wavelengths is a topical problem.…”