Ciba-geigy Corporation

Eth Zurich

Boeing North American, Inc.

Rainbow Photonics Ag

Peter Gunter

Bernd Tieke

Mark D Ewbank

Patricia H Cunningham

Christian Bosshard

Gero Decher

Mark J Rosker

Christoph Hunziker

O-Pil Kwon

Harry Figi

Mojca Jazbinsek

Seong-Ji Kwon

Arno Schneider

The invention concerns Phenolic Configurationally Locked Polyene Single Crystals, which are especially suited as highly efficient nonlinear optical organic material. The invention also concerns methods for growth of crystalline thin films or bulk crystals from melt and/or solution. The compounds are suited and the methods may be used for manufacturing optical elements for several bulk and integrated applications, e.g. electro-Optics and THz-Wave applications.

Phenolic configurationally locked polyene bulk single crystals, crystalline thin films and waveguides for electro-optics and THz-wave applications

The invention relates to a broadband Terahertz (THz) radiation generation and detection system and method. THz radiation is generated by optical rectification of an ultrashort pump pulse of a first wavelength having a duration in the picosecond- or sub-picosecond range in a first nonlinear optical crystal. The THz radiation is detected by electro-optic sampling or another appropriate method of a probe beam having a second wavelength in a second nonlinear optical crystal. According to the invention, at least one of the following conditions is fulfilled: a) the first wavelength is different from the second wavelength; b) the material of the first nonlinear optical crystal is different from the material of the second nonlinear optical crystal. This makes it possible to choose for the generation and for the detection process&#x2014;independent of one another&#x2014;the combination of wavelengths and nonlinear material and possibly other features of the pump/probe pulses like polarization with the highest efficiency for generation and detection of Terahertz pulses, respectively.

Broadband Terahertz radiation generation and detection system and method

A family of cesium-germanium halide salts have utility as nonlinear optical crystals in applications including electro-optics and optical frequency conversion. These salts have the general formula CsGeCl.sub.x Br.sub.y I.sub.z, in which x, y, and z equal 0 through 3, inclusive, and where x+y+z=3. In contrast to well-known oxygen-containing materials, such as LiNbO.sub.3, these cesium-germanium halide salts exhibit optical nonlinearity with an extremely wide transparency range (without significant absorption) at wavelengths from about 0.4 .mu.m to greater than 25 .mu.m (covering the entire MWIR and LWIR regions). Based on Ge.sup.2+ ions, these halides have non-centrosymmetric perovskite structures. The halide ions form a strongly coordinating octahedral environment about the Ge.sup.2+ ions and resist migration in an electric field. The Ge2+ ions, however, are shifted slightly off center in the tetragonal phase, leading to a net electric dipole moment in each unit cell. The alignment of these dipole moments into ferroelectric domains can be controlled through applied electric fields. By aligning all dipole moments into a single ferroelectric domain, these cesium-germanium halides have utility for electro-optic and birefringently phase-matched frequency conversion devices. Alternately, periodic poling of the ferroelectric domains allows these materials to be used for quasi-phase-matched frequency conversion. Cesium-germanium halide salts, which can be isolated from aqueous solutions as salts of GeX.sub.3 .sup.- anions, are water-soluble, which facilitates large-aperture crystal growth.

Cesium-germanium halide salts forming nonlinear optical crystals

A material in the form of a film is described which contains, in an orientated arrangement which does not display point symmetry, compounds of formula I ##STR1## wherein X is .dbd.CH-- or .dbd.N--, R.sup.1 is C.sub.12 -C.sub.30 -alkyl, R.sup.2 is hydrogen or C.sub.1 -C.sub.30 -alkyl, R.sup.3 is --NO.sub.2, --CN, --CF.sub.3, --COCF.sub.3, --SO.sub.2 CH.sub.3 or --SO.sub.2 CF.sub.3, R.sup.4 is hydrogen or is defined in the same way as R.sup.3, R.sup.5 is hydrogen or --NR.sup.6 R.sup.7 and R.sup.6 and R.sup.7 independently of one another are hydrogen or C.sub.1 -C.sub.30 -alkyl, it also being possible for any of the alkyl radicals to be partially fluorinated or perfluorinated. The compounds of formula I can be arranged in Langmuir-Blodgett layer systems. Such systems can be used for example for the manufacture of opto-electronic units.

Organic materials with non-linear optical properties

Growing community of inventors

Riedt-Neerach, Switzerland

Peter Gunter