Large photorefractive effect in a thermally decomposed polymer compared with that in molecularly doped systems

Abstract

Photorefractive polymers with the same electro-optic effect were fabricated to investigate the photorefractive effects in different photoconductive systems. The photoconduction in the polymers was varied by the addition of squarylium dye to diethylaminobenzaldehyde-diphenylhydrazone (DEH), by the formation of a charge-transfer complex between tetracyanoquinodimethane and DEH, and by the thermal decomposition of DEH. The largest photorefractive effect was observed in the thermally decomposed polymer among these polymers. A diffraction efficiency of 1.1% and a beam-coupling gain coefficient of 10 cm−1 were achieved in a 34.9 V/μm dc electric field.

Reversible and irreversible index gratings in a NPP-doped low-Tgpolymer composite

“…However, the reported photorefractivity was relatively small due to the poor photoconductivity of the matrix [13]. For example, polycarbonate:tris-p-telylamine:NPP:C60 exhibited a two-beam coupling coefficient of 20 cm-' and a four-wave mixing diffraction efficiency of 3.4% [13]. In this work, NPP was tentatively doped in PVK:TNF:ECZ to form a new PR composite PVK:TNF:ECZ:NPP.…”

“…N-(4-nitropheny1)-(0-prolinol (NPP), one of the excellent nonlinear optical chromophore [ll], has previously been doped in several low Tg polymer composites as PR materials [ 12-1 51. However, the reported photorefractivity was relatively small due to the poor photoconductivity of the matrix [13]. For example, polycarbonate:tris-p-telylamine:NPP:C60 exhibited a two-beam coupling coefficient of 20 cm-' and a four-wave mixing diffraction efficiency of 3.4% [13].…”

Reversible and irreversible index gratings in a NPP-doped low-T<SUB>g</SUB> polymer composite

“…The high photorefractivity in these samples is attributed to a so-called orientational enhancement eå ect [10]. N-(4-nitrophenyl)-(l)-prolinol (NPP), one of the excellent nonlinear optical chromophore [11], has previously been doped in several low T g polymer composites as PR materials [12][13][14][15]. However, the reported photorefractivity was relatively small due to the poor photoconductivity of the matrix [13].…”

“…N-(4-nitrophenyl)-(l)-prolinol (NPP), one of the excellent nonlinear optical chromophore [11], has previously been doped in several low T g polymer composites as PR materials [12][13][14][15]. However, the reported photorefractivity was relatively small due to the poor photoconductivity of the matrix [13]. For example, polycarbonate:tris-p-telylamine:NPP:C 60 exhibited a two-beam coupling coeae cient of 20 cm -1 and a four-wave mixing diå raction eae ciency of 3.4% [13].…”

“…However, the reported photorefractivity was relatively small due to the poor photoconductivity of the matrix [13]. For example, polycarbonate:tris-p-telylamine:NPP:C 60 exhibited a two-beam coupling coeae cient of 20 cm -1 and a four-wave mixing diå raction eae ciency of 3.4% [13]. In this work, NPP was tentatively doped in PVK:TNF:ECZ to form a new PR composite PVK:TNF:ECZ:NPP.…”