Abstract: An apparatus for time-resolved capture of pulsed electromagnetic radio frequency radiation includes a generator being so adapted that in operation of the apparatus the generator produces pulses of the electromagnetic radio frequency radiation, a detector being so adapted that in operation of the apparatus the detector captures the field strength of the pulses reflected by a sample as a function of time, and a distance measurement system and an evaluation device connected to the detector and the distance measurement system. The distance measurement system is so adapted that in operation of the apparatus the distance measurement system captures a change in a distance between the generator and the sample and/or between the sample and the detector as a function of time.

Abstract: A compressible photonic crystal comprising a polymer with an ordered array of voids, the photonic crystal having a reflectance in a first wavelength range for light incident to its incident surface and its opposing incident surface; wherein compression against at least a portion of at least one of the surfaces shifts the reflectance to a second wavelength range in at least that portion of that surface. The crystal may be used in authentication devices of various types.

Abstract: An optical arrangement has a laser configured to emit a laser beam, an amplitude mask and a focusing element. The amplitude mask is disposed between the laser and the focusing element in a path of the laser beam such that the laser beam hits the amplitude mask before being modified by the focusing element so as to direct the laser beam to a focal point within a photosensitive material.

Abstract: A method for laser beam machining of a workpiece in which a laser beam is focused by an objective, into or onto the workpiece having a boundary surface, to produce a machining effect by a two-photon process, and the position of the focal point with respect to the workpiece is shifted. To obtain a reference for the position of the focal point, an image of a luminating modulation object is projected through the objective onto the workpiece into the focal plane or so as to intersect it. Reflections of the image occurring at the boundary surface are imaged into an autofocus image plane, and are detected by a camera. The camera image plane either intersects the autofocus image plane when the image of the illuminating modulation object lies in the focal plane, or lies in the autofocus image plane when the image of the modulation object intersects the focal plane.

Abstract: The invention relates to a process for producing a photonic crystal which consists of a material of high refractive index, comprising the following process steps: a) providing a polymer structure with crosslinked air pores, whose surface has empty interstitial sites, b) applying a homogeneous, isotropic thin coating material to the surface of the polymer structure, c) introducing a high-index material, d) opening up a route to the polymer or to the coating material applied in step b), e) removing the layer applied in step b), f) removing the polymeric structure.

Abstract: An optical arrangement has a laser configured to emit a laser beam, an amplitude mask and a focusing element. The amplitude mask is disposed between the laser and the focusing element in a path of the laser beam such that the laser beam hits the amplitude mask before being modified by the focusing element so as to direct the laser beam to a focal point within a photosensitive material.

Abstract: A method of using a chemical compound as an etchant for the removal of unmodified areas of a chalcogenide-based glass, while leaving the imagewise modified areas un-removed, wherein the compound contains a secondary amine, R1 R2 NH, with R1 and/or R2 having a sterically bulky group with more than 5 atoms.

Abstract: A method for laser beam machining of a workpiece in which a laser beam is focused by an objective, into or onto the workpiece having a boundary surface, to produce a machining effect by a two-photon process, and the position of the focal point with respect to the workpiece is shifted. To obtain a reference for the position of the focal point, an image of a luminating modulation object is projected through the objective onto the workpiece into the focal plane or so as to intersect it. Reflections of the image occurring at the boundary surface are imaged into an autofocus image plane, and are detected by a camera. The camera image plane either intersects the autofocus image plane when the image of the illuminating modulation object lies in the focal plane, or lies in the autofocus image plane when the image of the modulation object intersects the focal plane.

Abstract: A compressible photonic crystal comprising a polymer with an ordered array of voids, the photonic crystal having a reflectance in a first wavelength range for light incident to its incident surface and its opposing incident surface; wherein compression against at least a portion of at least one of the surfaces shifts the reflectance to a second wavelength range in at least that portion of that surface. The crystal may be used in authentication devices of various types.

Abstract: The invention relates to a process for producing a photonic crystal which consists of a material of high refractive index, comprising the following process steps: a) providing a polymer structure with crosslinked air pores, whose surface has empty interstitial sites, b) applying a homogeneous, isotropic thin coating material to the surface of the polymer structure, c) introducing a high-index material, d) opening up a route to the polymer or to the coating material applied in step b), e) removing the layer applied in step b), f) removing the polymeric structure.

Abstract: A method of using a chemical compound as an etchant for the removal of unmodified areas of a chalcogenide-based glass, while leaving the imagewise modified areas un-removed, wherein the compound contains a secondary amine, R1 R2 NH, with R1 and/or R2 having a sterically bulky group with more than 5 atoms.

Abstract: The present invention provides a straightforward and robust synthetic process for producing a chromatographic column with eluent-sensitive light diffracting properties based on an inherent photonic band structure and a chromatographic device using the chromatographic column. The present invention provides chromatographic devices employing a chromatographic column which in one embodiment is a photonic colloidal crystal which includes an assembly of colloidal microspheres assembled into a highly ordered array within a housing such as a tube with the highly ordered array being a photonic crystal along the length of the crystal, and a second embodiment which is an inverse construct of the first embodiment, where solid microspheres making up the photonic colloidal crystal chromatographic column are replaced with spherical voids or void spaces subsequent to infiltration of a material of selected refractive index.

Abstract: The present invention provides a straightforward and robust synthetic process for producing a chromatographic column with eluent-sensitive light diffracting properties based on an inherent photonic band structure and a chromatographic device using the chromatographic column. The present invention provides chromatographic devices employing a chromatographic column which in one embodiment is a photonic colloidal crystal which includes an assembly of colloidal microspheres assembled into a highly ordered array within a housing such as a tube with the highly ordered array being a photonic crystal along the length of the crystal, and a second embodiment which is an inverse construct of the first embodiment, where solid microspheres making up the photonic colloidal crystal chromatographic column are replaced with spherical voids or void spaces subsequent to infiltration of a material of selected refractive index.