摘要:
A suction system is arranged in a sheet guiding cylinder of a printing machine which is switchable from the first form mode to the printing on both sides of the sheet which is turned over by the suction system around its rear edge. The suction system includes an arrangement for automatically controlling suction air for operating a suction head which is movable in a sucker body of the suction system.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
The invention relates to new films for applying to a substrate and to methods for producing them.A composition, for use in preparing a film, (preferably an epitactic film) comprising a solid solution of KNbO.sub.3 and KTaO.sub.3 forming a product of formula IK.sub.1-y M.sub.y Ta.sub.1-x Nb.sub.x O.sub.3 (I)in which M is a monovalent metal ion other than K.sup.+ (hereinafter defined as the dopant);y=0.02 to 0.20 andx=0.05 to 0.95.
摘要:
Single domain crack-free and striation-free KNbO.sub.3 crystals having a maximum iron content of 15 ppm, a process for the synthesis of such crystals and laser systems comprising single domain crack-free and striation-free KNbO.sub.3 crystals which systems convert green light of wavelength 500-540 nm into blue light of wavelength 430-470 nm.
摘要:
A method of producing a device with a ferroelectric crystal thin film on a first substrate including the steps of providing a ferroelectric crystal, of irradiating a first surface of the ferroelectric crystal with ions so that a damaged layer is created underneath the first surface, of bonding a block of material including the first substrate to the ferroelectric crystal to create a bonded element, wherein an interface is formed between the first surface and a second surface of the block, and of heating the bonded element and separating it at the damaged layer, so that a ferroelectric crystal layer remains supported by the first substrate. By this method, very thin films—down to thicknesses of a fraction of a micrometer—of ferroelectric crystals may be fabricated without jeopardizing the monocrystalline structure.
摘要:
The process for the manufacture of the rib waveguide (4) is based on the process steps (a) ion implantation of high-energy light ions into a crystal, (b) the application of a mask to the surface (11.1) of this crystal, which defines strips, and (c), the etching of a rib (41) onto the surface (11.1) of this crystal. The process step (a) (ion implantation) causes the formation of a layer (14) with a reduced refraction index at a depth of some micrometers below the surface of the crystal (11.1). By this refraction index barrier (14), the light in the direction vertical to the surface of the crystal is restricted. The lateral guidance of the light is effected by the lateral limits (43.1) and (43.2) of the rib (41). The process is in particular suitable for the manufacture of waveguides in non-linear optical crystals, e.g., ferro-electric oxides (KNbO3, LiNbO3, etc.) and borates (LBO, BBO, etc.). These crystal classes have interesting non-linear-optical characteristics and are suitable for utilization as frequency converters. The manufacturing process in accordance with the invention, in particular the combination of ion implantation and the etching of a rib structure, is adapted to the particular characteristics of the material and enables the manufacture of rib waveguides with a low attenuation, whereby the non-linear optical characteristics of the crystal are maintained. This is an important prerequisite for achieving an efficient frequency conversion.
摘要:
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.
摘要:
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—independent of one another—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.