Abstract: A device includes a grating coupler with a grating constant, two light sources, and a planar waveguide, which are configured to couple light with two different wavelengths ?1, ?2 into the waveguide. The waveguide has a waveguiding layer disposed adjacent to a substrate layer and a cover layer. The waveguiding layer has a thickness d and effective refractive indices of N(?k, jk), wherein ?k is one of the wavelengths and jk is an order of a waveguide mode, wherein the coupled light of the wavelength ?k has a coupling angle ?k into the waveguide, and wherein an amount of difference between the coupling angles is a divergence angle ??. Guiding of waveguide modes of the order jk>0 is possible for a wavelength of the coupled light. The waveguiding layer is arranged to couple the light via the grating coupler under a divergence angle of ??<6.

Abstract: A diffractive biosensor for the selective detection of biomolecules includes a substrate and an optical biograting situated on the substrate, the biograting having periodically arranged receptors for the biomolecules and the efficiency of a diffraction of incident light, and thus the intensity of a measuring light beam arriving in a detector, is a function of a mass coverage of the biograting with the biomolecules to be detected. The biosensor has a device for generating a reference light beam directed to the detector, by which the phase position of stray light arriving in the detector is able to be determined.

Abstract: A device includes a grating coupler with a grating constant, two light sources, and a planar waveguide, which are configured to couple light with two different wavelengths ?1, ?2 into the waveguide. The waveguide has a waveguiding layer disposed adjacent to a substrate layer and a cover layer. The waveguiding layer has a thickness d and effective refractive indices of N(?k, jk), wherein ?k is one of the wavelengths and jk is an order of a waveguide mode, wherein the coupled light of the wavelength ?k has a coupling angle ?k into the waveguide, and wherein an amount of difference between the coupling angles is a divergence angle ??. Guiding of waveguide modes of the order jk>0 is possible for a wavelength of the coupled light. The waveguiding layer is arranged to couple the light via the grating coupler under a divergence angle of ??<6.

Abstract: A diffractive biosensor for selective detection of biomolecules includes a substrate and a flat waveguide disposed on the substrate. The waveguide has an optical grating configured to couple incident light into the waveguide such that the light is guided through the waveguide to a detection region located behind an edge of the waveguide. The in-coupling efficiency and intensity of the light arriving in the detection region are dependent on a surface coverage of the optical grating with the biomolecules to be detected. The optical grating has receptors for the biomolecules periodically arranged on the waveguide. The light incident on the optical grating is collimated.

Abstract: An internal-combustion engine with a turbocharger is suggested, in the case of which a limiting of the exhaust gas counterpressure is provided in the braking operating mode of the internal-combustion engine.

Abstract: In an exhaust gas turbocharger turbine for an internal combustion engine with a turbine housing having an annular flow path, a control sleeve axially movably supported in an annular space formed in the turbine housing adjacent the annular flow path and having at its front end a flow guide structure with vanes for guiding the exhaust gas flow when the flow guide structure is disposed in the annular flow path, a ring is disposed at the front end of the control sleeve in front of the flow guide structure such that the annular space is covered and sealed when the control sleeve is fully retracted into the annular space whereby flow losses are substantially reduced.

Abstract: In an exhaust gas turbocharger turbine for an internal combustion engine including a turbine housing with a turbine wheel disposed therein, an axially movable slide member having a front end with a vane structure is disposed in an annular gap formed in the turbine housing adjacent a radial flow passage leading to the turbine wheel such that the annular slide member is movable between a first position in which its vane structure is disposed in the radial flow passage and a second position in which the vane structure is received within the annular gap and blow off passages which extend through the turbine housing from the radial flow passage through the annular gap to the discharge side of the turbine are opened when the annular slide member is further retracted for discharging gas from the radial flow passage to the turbine discharge side while by-passing the turbine.