Abstract: Aqueous leucoindigo solution comprising an aromatic amine, in particular aniline or aniline and N-methylaniline, wherein the concentration of the aromatic amine is below 200 ppm, wherein the leucoindigo salt in the solution is in the form of a mixed sodium and potassium salt, wherein the molar ratio of sodium to potassium is in the range of from above 3:1 to 10:1, preferably wherein the concentration of the salt is in the range of from above 25 to 45% by weight, based on the total weight of the solution.

Abstract: Stable aqueous leucoindigo solution comprising an aromatic amine in the form of aniline or aniline and N-methylaniline, wherein said leucoindigo is in the form of an alkali metal salt; wherein the concentration of the aromatic amine is below 40 ppm determined according to ISO 14362-1:2017(E); and wherein the concentration of the leucoindigo salt is in a concentration range of from 10 to 45% by weight based on the total weight of the solution, and wherein the stability of the solution is measured at a temperature of 23° C.; or wherein the concentration of the leucoindigo salt is in a concentration range of from 45 to 65% by weight based on the total weight of the solution, and wherein the stability of the solution is measured at a temperature of 60° C.

Abstract: Stable aqueous leucoindigo solution comprising an aromatic amine in the form of aniline or aniline and N-methylaniline, wherein said leucoindigo is in the form of an alkali metal salt; wherein the concentration of the aromatic amine is below 40 ppm determined according to ISO 14362-1:2017(E); and wherein the concentration of the leucoindigo salt is in a concentration range of from 10 to 45% by weight based on the total weight of the solution, and wherein the stability of the solution is measured at a temperature of 23° C.; or wherein the concentration of the leucoindigo salt is in a concentration range of from 45 to 65% by weight based on the total weight of the solution, and wherein the stability of the solution is measured at a temperature of 60° C.

Abstract: Aqueous leucoindigo solution comprising an aromatic amine, in particular aniline or aniline and N-methylaniline, wherein the concentration of the aromatic amine is below 200 ppm, wherein the leucoindigo salt in the solution is in the form of a mixed sodium and potassium salt, wherein the molar ratio of sodium to potassium is in the range of from above 3:1 to 10:1, preferably wherein the concentration of the salt is in the range of from above 25 to 45% by weight, based on the total weight of the solution.

Abstract: Method of making an aqueous aniline-free or aniline-free and N-methylaniline-free leucoindigo solution from an aqueous leucoindigo solution comprising aniline or aniline and N-methylaniline, the concentration of aniline or aniline and N-methylaniline being determined according to ISO 14362-1:2017(E), wherein said leucoindigo is in the form of an alkali metal salt, the method comprising at least steps (A) to (C): (A) providing a liquid stream comprising said aqueous leucoindigo solution comprising said amine(s); (B) providing a purification stream; (C) bringing into contact said liquid stream with said purification stream.

Abstract: Aqueous leucoindigo solution comprising an aromatic amine in the form of aniline or aniline and N-methylaniline, wherein said leucoindigo is in the form of an alkali metal salt; wherein the concentration of the aromatic amine is below 40 ppm determined according to ISO 14362-1:2017(E); and wherein the concentration of the leucoindigo salt is in a concentration range of from 15 to 45% by weight based on the total weight of the solution, and wherein the solution is stable at a temperature of 23° C.; or wherein the concentration of the leucoindigo salt is in a concentration range of from 45 to 65% by weight based on the total weight of the solution, and wherein the solution is stable at a temperature of 60° C.

Abstract: The present invention relates to a micro total analysis system comprising a spectroscope and a method of manufacturing such a system comprising a spectroscope in a one step process. More over the invention relates to a method of analyzing a sample in the system. The micro total analysis system comprising a spectroscope provided on a substrate and for measuring electromagnetic radiation and at least one microfluidic channel. The spectroscope comprises: a slab waveguide for guiding electromagnetic waves towards a diffraction grating dispersing the electromagnetic waves into their component wavelengths, and output means for receiving the deflected electromagnetic waves. At least a part of the microfluidic channel, the slab waveguide and the grating comprises the same main material, such as a polymer material.

Abstract: A set of three gratings may be operated in a vernier loop fashion to select a particular wavelength from a wavelength division multiplexed system. As a result, an optical add/drop multiplexer may be provided that can be tuned to select a desired wavelength. In one embodiment, the tuning may be done thermo-optically.

Abstract: An optical analysis device having a gastight housing, a radiation-permeable housing element, at least a first radiation source and associated first reflector and a second radiation source and associated second reflector, at least first and second detectors, and an external reflector. The radiation sources and the detectors are located within the housing, an absorption space being formed between the external reflector and the radiation-permeable housing element. A measurement beam emitted by the first radiation source and the first reflector, after reflection on the external reflector, re-enters the housing. A reference beam is emitted by the second radiation source and the second reflector. The measurement beam, after crossing the absorption space, is guided from the measurement beam reflector directly onto the first detector and the second detector and the reference beam from the second radiation source is directly incident on the first detector and the second detector.

Abstract: A set of three gratings may be operated in a vernier loop fashion to select a particular wavelength from a wavelength division multiplexed system. As a result, an optical add/drop multiplexer may be provided that can be tuned to select a desired wavelength. In one embodiment, the tuning may be done thermo-optically.

Abstract: A set of three gratings may be operated in a vernier loop fashion to select a particular wavelength from a wavelength division multiplexed system. As a result, an optical add/drop multiplexer may be provided that can be tuned to select a desired wavelength. In one embodiment, the tuning may be done thermo-optically.

Abstract: A set of three gratings may be operated in a vernier loop fashion to select a particular wavelength from a wavelength division multiplexed system. As a result, an optical add/drop multiplexer may be provided that can be tuned to select a desired wavelength. In one embodiment, the tuning may be done thermo-optically.

Abstract: A set of three gratings may be operated in a vernier loop fashion to select a particular wavelength from a wavelength division multiplexed system. As a result, an optical add/drop multiplexer may be provided that can be tuned to select a desired wavelength. In one embodiment, the tuning may be done thermo-optically.

Abstract: A set of three gratings may be operated in a vernier loop fashion to select a particular wavelength from a wavelength division multiplexed system. As a result, an optical add/drop multiplexer may be provided that can be tuned to select a desired wavelength. In one embodiment, the tuning may be done thermo-optically.

Abstract: A system and method are provided for writing refractive index structures, such as gratings, in an optical waveguide. There is no requirement for structures having interferometric stability of the control elements. The method includes providing first and second light beams, the first beam having a first polarization state and a first wavevector, the second beam having a second polarization state different from the first polarization state, and a second wavevector different from the first wavevector. The method also includes illuminating a diffractive optical element by at least a part of the first beam and a part of the second beam so as to diffract parts of the first and second beams, and positioning the medium in relation to the diffractive element so as to illuminate the first part of the medium by the diffracted parts of the first and second beams.

Abstract: A method of producing an active optical waveguide having asymmetric polarization, said method comprising the steps of (a) providing an active optical waveguide (10) comprising: (i) a transverse refractive index profile (21) comprising a guiding region (11), an intermediate region (13), and a non-guiding region (12); (ii) a transverse photorefractive dopant profile (31) comprising a constant or graded photorefractive dopant concentration within at least one of the guiding, non-guiding and intermediate regions, except that the photorefractive dopant is not located solely in the guiding region; and (iii) exhibiting in said guiding region, intermediate region, or both, light guiding modes having different polarizations; and (b) exposing at least a part (10a, 10b) of the active optical waveguide to an effective transverse illumination of light (20) reacting with the photorefractive dopant and modifying said transverse refractive index profile; said part of the active optical waveguide being exposed to a fluence se