Abstract: A two-dimensional, temporally modulated electromagnetic wavefield, preferably in the ultraviolet, visible or infrared spectral range, can be locally detected and demodulated with one or more sensing elements. Each sensing element consists of a resistive, transparent electrode (E) on top of an insulated layer (O) that is produced over a semiconducting substrate whose surface is electrically kept in depletion. The electrode (E) is connected with two or more contacts (C1; C2) to a number of clock voltages that are operated synchronously with the frequency of the modulated wavefield. In the electrode and in the semiconducting substrate lateral electric fields are created that separate and transport photogenerated charge pairs in the semiconductor to respective diffusions (D1; D2) close to the contacts (C1; C2).

Abstract: A two-dimensional, temporally modulated electromagnetic wavefield, preferably in the ultraviolet, visible or infrared spectral range, can be locally detected and demodulated with one or more sensing elements. Each sensing element consists of a resistive, transparent electrode (E) on top of an insulated layer (O) that is produced over a semiconducting substrate whose surface is electrically kept in depletion. The electrode (E) is connected with two or more contacts (C1; C2) to a number of clock voltages that are operated synchronously with the frequency of the modulated wavefield. In the electrode and in the semiconducting substrate lateral electric fields are created that separate and transport photogenerated charge pairs in the semiconductor to respective diffusions (D1; D2) close to the contacts (C1; C2).

Abstract: The effective photosensitive area of a solid-state photosensor is controlled with a multitude of electrodes (E1, . . . , Ei, . . . , En) on top of an insulator layer (O) covering a semiconductor substrate (S). Photogenerated charge carriers move laterally under the influence of the voltage distribution on the various electrodes (E1, . . . , Ei, . . . , En), and they are collected at the two ends of the photosensor in diffusions (D1, D2). The voltage distribution on the electrodes (E1, . . . , Ei, . . . , En) is such that the voltage at the two furthermost electrodes (E1, En) is maximum (if photoelectrons are collected), minimum at an interior electrode (Ei), and monotonously decreasing in between. The lateral position of the electrode (Ei) with minimum voltage defines the effective photosensitive area of the photosensor.

Abstract: A compressor includes a casing defining a generally cylindrical flow passage, a rotor carrying at least one set of rotor blades, at least one set of stator blades, and anti-stall casing treatment. The casing treatment includes an annular recess in the casing for removing low momentum flow adjacent the tips of the rotor blades, and returning the flow to the generally cylindrical flow passage upstream of the point of removal. A plurality of curved guide vanes are located within the annular recess so as to define an annular inlet downstream of the vanes and/or an annular outlet upstream of the vanes. Each guide vane projects radially inwardly from the casing towards a free end which is exposed at or near the mouth of the recess to define a series of curved channels within the recess adjacent the annular inlet and/or the annular outlet.

Abstract: An apparatus for the contact-less, interferometric investigation of a sample object (2), particularly for the determination of sample surface profiles and depth profiles of light scattering properties of the sample (2), comprises a light source (1), able to provide broadband, low-coherence light; a beam splitter (4), arranged to split up a source light beam (11) produced by the light source (1) into a reference light beam (31) and an object light beam (21), and arranged to recombine a reflected reference light beam (31?) and a reflected object light beam (21?) to a detection light beam (51); a reference mirror element (3), arranged to reflect said reference light beam (31) back to the beam splitter (4); and a one- or two-dimensional photo sensor (5), able to convert incident light of said detection light beam (51) to an electric current signal.

Abstract: An optically reflective or translucent object (14) can be microscopically imaged in all three dimensions and in true color for observation by a human observer. An interferometric optical setup is employed, using the low temporal coherence of a tunable broad-band light source (10, 20) to resolve the axial dimension, a single opto-mechanical or electronic scanning mechanism for accessing different object depths, and a two-dimensional photo sensor device (15, 34) capable of demodulating the temporally or spatially modulated scanning signals to reconstruct the object's full volume. Three volume scans are carried out sequentially, and the tunable broad-band source (10, 20) is operated in such a way that its spectral distribution for each of the volume scans results in an effective system sensitivity corresponding to one of the three CIE (Commission Internationale d'Éclairage) tristimulus curves, or a linear combination thereof.

Abstract: An imaging optical coherence tomography (OCT) apparatus with high transverse and high axial resolution comprises an interferometer of the Michelson, Mach-Zehnder or Kosters type. Light returning in the reference beam path (27) and the object beam path (26) interferes and is detected by an image sensor (28, 45) in the detection beam path (25). A single electromechanical linear scanner displaces the plane reference mirror (34, 51), the object imaging lens (33, 50), and the reference imaging lens (35, 52) along the optical axis. By providing identical lenses in the reference beam path (27) and in the object beam path (26), the geometrical displacement of the measurement focus in the object beam path (26) is equal to the change in optical length in the reference beam path (27), thus allowing dynamic coherent focus over the full scanning distance. All optical elements that must be replaced to obtain a different optical magnification can be arranged in an exchangeable cartridge (32, 49).

Abstract: A solid-state image sensor (1) with very high sensitivity approaching the single-photon limit is realized with three modular building blocks: (a) a pixel (2.11, 2.12, . . . ) with a photo-site, intermediate photo-charge storage capability as used for correlated double sampling, and an electronic circuit for signal buffering or amplification, (b) a column or row signal line (3.1) to which a plurality of such pixels (2.11, 2.21, . . . ) is connected using transistor switches, incorporating a low-pass filter (30.1), and (c) a readout circuit (4) to which the row signal lines (3.1, 3.2, . . . ) are connected, consisting of a plurality of analog amplifiers (41.1, 41.2, . . . ) with an analog multiplexer (42). Photo-generated signals are read out and the reset level is subtracted either in the analog or in the digital domain, to implement a correlated-double-sampling method.

Abstract: A turbocompressor flow structure comprises a ring chamber which is arranged concentrically to an axis of a turbocompressor in an area of free blade/vane ends of a rotor blade ring/vane ring and is adjacent radially to a main flow channel. A ring chamber is provided which is bordered by a front upstream wall, a rear downstream wall and a wall that runs essentially axially. Baffle elements are arranged in the ring chamber and the ring chamber permits flow penetration in a circumferential direction in a front and/or rear area. At least one opening is provided in the area of the wall that runs essentially axially or in the area of the upstream wall and permits flow penetration out of the ring chamber, at least one compressor chamber being provided to accommodate this outgoing flow.

Abstract: The pixel for use in an image sensor comprises a low-doped semiconductor substrate (A). On the substrate (A), an arrangement of a plurality of floating areas e.g., floating gates (FG2-FG6), is provided. Neighboring floating gates are electrically isolated from each other yet capacitively coupled to each other. By applying a voltage (V2-V1) to two contact areas (FG1, FG7), a lateral steplike electric field is generated. Photogenerated charge carriers move along the electric-field lines to the point of highest potential energy, where a floating diffusion (D) accumulate the photocharges. The charges accumulated in the various pixels are sequentially read out with a suitable circuit known from image-sensor literature, such as a source follower or a charge amplifier with row and column select mechanisms. The pixel of offers at the same time a large sensing area, a high photocharge-detection sensitivity and a high response speed without any static current consumption.

Abstract: A recirculation structure for turbo-compressors has an annular chamber that is positioned in the area of the free blade ends of a rotating blade ring and that radially borders the main flow channel, and has a multitude of guide vanes arranged in the annular chamber and distributed around its circumference. The annular chamber enables the passage of air flow in the forward and/or rear areas, and the guide vanes are firmly fixed to at least one wall of the annular chamber and otherwise are designed to be free-standing. The tips of the guide vanes that face the annular chamber extend along and/or near the contour of the main flow channel, and axially overlap the free blade ends or axially border the area of the free blade ends.

Abstract: A device and method for spatially resolved photodetection and demodulation of temporally modulated electromagnetic waves makes it possible to measure phase, amplitude and offset of a temporally modulated, spatially coded radiation field. A micro-optical element (41) spatially averages a portion (30) of the scene and equally distributes the averaged intensity on two photo sites (51.1.51.2) close to each other. Adjacent to each of these photo sites (51.1) are two storage areas (54.1, 54.2) into which charge from the photo site can be moved quickly (with a speed of several MHz to several tens or even hundreds of MHz) and accumulated essentially free of noise. This is possible by employing the charge-coupled device (CCD) principle. The device combines a high optical fill factor, insensitivity to offset errors, high sensitivity even with little light, simultaneous data acquisition, small pixel size, and maximum efficiency in use of available signal photons for sinusoidal as well as pulsed radiation signals.

Abstract: A two-dimensional, temporally modulated electromagnetic wavefield, preferably in the ultraviolet, visible or infrared spectral range, can be locally detected and demodulated with one or more sensing elements. Each sensing element consists of a resistive, transparent electrode (E) on top of an insulated layer (O) that is produced over a semiconducting substrate whose surface is electrically kept in depletion. The electrode (E) is connected with two or more contacts (C1; C2) to a number of clock voltages that are operated synchronously with the frequency of the modulated wavefield. In the electrode and in the semiconducting substrate lateral electric fields are created that separate and transport photogenerated charge pairs in the semiconductor to respective diffusions (D1; D2) close to the contacts (C1; C2).

Abstract: A modulated optical radiation field (I) whose modulation amplitude and temporal phase depend on the local position can be detected with a plurality of pixels 1. Each pixel 1 consists of a transducing stage (T) that converts incoming light (I) into a proportional electric signal, a sampling stage (S), two subtraction/summation stages (SUB1, SUM1; SUB2, SUM2), and an output stage. Each pixel can be addressed individually. The optical radiation field (I) is locally sensed and sampled at a frequency that is four times the wavefield's modulation frequency. The subtraction/summation stages (SUB1, SUM1; SUB2, SUM2) accumulate differences of two samples per modulation period, separated by half the period, during several averaging periods; the two stages are time shifted with respect to each other by a quarter period. The resulting two output signals are employed for the determination of the local envelope amplitude and the temporal phase.

Abstract: The monolithic integration of all key photonic components (11–16) of an integrated-optical microsystem (1) based on organic semiconductors is disclosed. Examples of such components (11–16) are light sources (11), photodetectors (12), photovoltaic power generators (12), field-effect transistors (13, 14), resistors, capacitors (15), or waveguiding structures (11, 12). The components (11–16) are arranged on a common substrate (20), are compatible with each other, can be manufactured simultaneously and can be operated simultaneously. At least one of the components (11–14) comprises a layer (23) of organic semiconductor material. Each component (11–16) comprises a plurality of layers (21–26), at least one of which (21) has identical physical and chemical characteristics in at least two components (11–16).

Abstract: Recirculation structure for turbocompressors, having a ring chamber which is arranged in the area of the free blade ends of a blade ring largely upstream of the latter and adjoins the main flow duct. A plurality of guiding elements are arranged in the ring chamber distributed over its circumference and are arranged and shaped in a fluidically advantageous manner with respect to the recirculation flow, with recesses provided in the leading and/or trailing area of the ring chamber. The side of the ring chamber which adjoins the contour of the main flow duct is open along its axial length as well as along its entire circumference, the free edges of the guiding elements being situated on the or close to the contour of the main flow duct.

Abstract: The method for forming an image with a wide dynamic range makes use of an image sensor containing subsets of pixels that can be individually reset. After an initial reset (21), a pixel or row of pixels is exposed (22) for a first time interval and the gray value(s) (Plong(255)) are read out (23) and stored (24). The pixel or row of pixels is then reset (25) and exposed (26) for a second, shorter time interval. The second gray value(s) (Pshort(255)) is/are read out (27) and either stored or immediately combined (28) with the first gray value(s) (Plong(255)) by means of a merging function (ƒ). The merging function (ƒ) ensures a monotonic, smooth change in output from the lowest to the highest gray values. The procedure is repeated for all pixels or rows of pixels in the image sensor, thus obviating the need for the storage of complete images. The method reduces temporal aliasing to a minimum and eliminates spatial aliasing.

Abstract: A photodiode (1) in a conventional photodetector-pixel architecture is supplied with a shunt diode (2) connected to a control voltage (V0). Suitable selection of the constant or time-varying control voltage (Vc) allows a combination of linear and non-linear, preferably logarithmic illumination response of the photodiode (1), resulting in a high dynamic photodetecting range of more than five orders of magnitude. The properties of the shunt diode (2) and the control voltage (Vc) can be chosen such that the resulting dark current matches the dark current of the photodiode (1), which becomes independent of voltage for high temperatures. This enables photodetecting with a sufficient dynamic range at higher temperatures than possible with conventional photodetectors.

Abstract: A recirculation structure for turbo-compressors has an annular chamber that is positioned in the area of the free blade ends of a rotating blade ring and that radially borders the main flow channel, and has a multitude of guide vanes arranged in the annular chamber and distributed around its circumference. The annular chamber enables the passage of air flow in the forward and/or rear areas, and the guide vanes are firmly fixed to at least one wall of the annular chamber and otherwise are designed to be free-standing. The tips of the guide vanes that face the annular chamber extend along and/or near the contour of the main flow channel, and axially overlap the free blade ends or axially border the area of the free blade ends.

Abstract: An electronic camera can be reprogrammed, recalibrated or optimized for a given application or environment by a remote expert who does not have to be present locally. The camera requires a bi-directional data path to the expert, preferably using the internet, for writing parameters into the camera's program memory and for reading its acquired images. The remote expert must be capable of presenting selected visual stimuli to the camera, which are presented by a suitable image presentation device to the camera, under remote control by the expert. Thanks to the invention, a recalibration of the camera is more simple, faster, at lower costs and independent of the location of the camera user.