Optically Nonlinear Films of Amphiphilic Polymers: Synthesis, Langmuir-Blodgett Deposition, and Optical Measurements

Abstract

Novel polymers are synthesized by attaching amphiphilic dye groups along a hydrophilic polyether backbone. These polymers are fabricated into noncentrosymmetric films by the Langmuir-Blodgett (L/B) technique. Stacks of molecular bi-layers are assembled by Y-type deposition, interleaving two different dye-substituted polymers. One polymer has the dye's molecular dipole pointing toward the backbone, while in the other polymer, the dye points in the opposite direction. Light from a Nd:YAG laser is passed through these films and the second harmonic is detected.

Mixed mono- and multilayers of poly(isocyanide)s with non-linear optically active side chains

“…NLO active functions have been incorporated in polymer matrices in the form of low molecular weight compounds [9,10] or have been introduced in the backbone [11] and side groups [12,13] of polymers.…”

Ordered Langmuir–Blodgett films derived from a mesogenic polymer amphiphile

“…Although many pre-formed polymers have been used for the fabrication of LB ®lms, there are far fewer examples which show a convincing layered structure by glancing angle XRD. Generally, these are based on a hydrophilic polymer, for example poly(maleic anhydride), 5±8 poly(ethyleneoxy) 25 or poly(acrylamide), 26 with hydrophobic side-chains. The present work demonstrates that it is possible to obtain an ordered LB ®lm from a hydrophobic polymer containing an appropriate side-chain.…”

Accordion Polymers for Nonlinear Optical Applications

“…The Langmuir-Blodgett-Kuhn (LBK) molecular layer deposition process has been utilized with both small molecules and polymers to give multilayer dipole-aligned films (7,8). The polymers designed for the present work have a syndioregic mainchain NLO polymer topology (3a) in which hydrophilic and lipophilic bridging groups are located on alternating bridging sites between the chromophores in order to bring about polar self-ordering at an air-water interface (27).…”

“…A chemical approach to the synthesis of thin hybrid organic/inorganic polar films by alternate deposition of chromophore and siliceous phase in a geometrically controlled fashion has produced stable intrinsically polar materials with attractive nonlinear optical properties (6 ). In addition, it is known that polar polymer films may be prepared by the use of the Langmuir-Blodgett-Kuhn (LBK) process (7). The fabrication of micron-thick films needed for guiding optical signals takes days by the LBK process, while the process for achieving stable polar order by electric field poling takes only a few hours.…”