Search Results - (Author, Cooperation:M. Eich)

2012-01-10

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

1077-3118

AIP Digital Archive

Physics

Extending our scanning second harmonic microscopy (SSHM) technique for the detection of lateral orientational inhomogeneities in high field poled polymer films, we present results with considerably improved lateral resolution by using optical fiber technology. Two experimental setups for measuring the χ(2) susceptibility of thin films are introduced. The first setup uses a standard monomode infrared-fiber with 10 μm core that carries the coherent fundamental infrared wave to the surface of a poled polymer film (illumination mode). The generated doubled frequency wave behind the nonlinear optical sample is detected by a photomultiplier tube. In the second setup a lens focuses the fundamental wave into the poled film. The resulting second harmonic wave is coupled into a 2.5 μm single mode fiber. SSHM micrographs of high field poled nonlinear optical polymer films were obtained with lateral resolutions of 〈3.5 μm. SSHM was also realized with a scanning near field optical microscopy fiber in pick up mode. © 1998 American Institute of Physics.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

We present details of the fabrication, calculations, and transmission measurements for finite two-dimensional (2D) polymer photonic crystal (PC) slab waveguides, which were fabricated from a benzocyclobutene polymer on a low refractive index substrate from Teflon. A square air hole lattice (500 nm lattice constant, 300 nm hole diameter) was realized by electron beam lithography and reactive ion etching. Polarization and wavelength dependent transmission results show TE-like and TM-like stop gaps at 1.3 μm excitation wavelengths and are in good agreement with the calculated data obtained by 2D and three-dimensional finite difference time domain methods. Transmission was suppressed by 15 dB in the center of the TE-like stop gap for a PC length of ten lattice constants. © 2001 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Thin films for optical second-harmonic generation (SHG) were prepared from a newly designed and synthesized amorphous polymer that incorporated a high density of active nonlinear optical groups (p-nitroaniline as attached side groups). For alignment of the nonlinear groups a very high electric field was applied by a corona discharge to the polymer films above Tg (125 °C). The subsequent freezing process resulted in a polymer film initially exhibiting a very high second-order nonlinear coefficient, d33=31 pm/V, measured by the Maker-fringe technique, plus excellent thermal, mechanical, and optical properties. The dynamics of polar alignment and decay, studied by in situ poling (or depoling) and SHG measurements, indicated a multiple exponential behavior with the average relaxation time somewhat longer than expected from extrapolation of the dielectric relaxations data according to the Williams–Landel–Ferry equation. The frozen-in SHG behavior at room temperature (∼100 °C below Tg) relaxed after 5 days to a stabilized value of 19 pm/V for d33.

Electronic Resource