Agilent Technologies, Inc.

Robert Boschgmbh

Wolf Steffens

Ulrich Kallmann

Emmerich Mueller

Bernd Nebendahl

Ralf Haeussler

Goetz Kuehnle

Jochen Schwarz

Volker Gross

Joerg Hilsebecher

Udo Haberland

Stefan Heilmann

Dirk Bechler

Klaus Lehre

Andre Treptow

Jens Heitkamp

Stephan Leinbaum

Hansjoerg Haisch

Sonja Eder

Andreas Schmidt

Michael Schubert

A radar sensor having multiple antenna elements for transmitting and receiving radar signals, an associated transmitting and receiving element and an evaluation device for determining the azimuth angle of located objects on the basis of a relationship between the signals received from different antenna elements, wherein the transmitting and receiving element is designed to supply to the antenna elements transmission signals in parallel, the frequencies of which are offset with respect to one another, and the evaluation device is designed to distinguish between signals that were transmitted by different antenna elements on the basis of the frequency offset.

Angular resolution radar sensor

A radar sensor having a corresponding evaluation and control device, which has a measuring mode for locating radar targets and a blindness detection device, which is configured to detect blinding of the radar sensor with the aid of the signals received by the radar sensor itself; wherein the evaluation and control device has a test mode, in which the radar sensor is controlled on the basis of parameters that are different from the parameters for the measuring mode and optimized for the blindness detection device, and the evaluation and control device has a switching device for switching over between the measuring mode and the testing mode.

Radar sensor having a blindness detection device

In a method for frequency matching in an FMCW radar sensor, a plurality of frequencies, which are derived on various modulation ramps, and which respectively are shown by the radar sensor in a d-v space as geometrical locations, represent possible combinations of a distance d and a speed v of the respective object. In order to identify the objects located on the various modulation ramps, coincidences between the geometrical locations which belong to frequencies derived on various modulation ramps are searched for. The search for coincidences is initially restricted in a first step to a subspace of the d-v space, and in a subsequent step, the search is extended to other regions of the d-v space, while suppressing the frequencies that are associated with the objects found in the first step.

FMCW radar sensor and method for frequency matching

A method for operating a radar, having the following steps: determining first and second differential signals from a first and second transmitted frequency-modulated signal and received components of the first and second transmitted frequency-modulated signal reflected by a plurality of objects; determining in each case one first and one second chirp signal for each first and the second differential signal, the first chirp signal corresponding to the double differentiation of the phase of the first and the second differential signal with respect to time; assigning one of the first differential signals to one of the second differential signals, based on a correspondence of the first chirp signal, that is assigned to the one first differential signal, to the second chirp signal that is assigned to the one second differential signal; and determining the separation distance and/or the relative speed of one of the objects, based on the one first differential signal and the one second differential signal assigned to the first differential signal.

Method for operating a radar and radar

A radar sensor for motor vehicles, having an optical system which subdivides a radar beam generated by a single antenna element into a plurality of beam components that are radiated in different directions, wherein the optical system has a diffraction grating.

Radar sensors for motor vehicles

A wavelength tunable cavity includes a first reflecting unit adapted to at least partially reflect a beam of electromagnetic radiation towards a second reflecting unit, adapted to at least partially reflect a beam of electromagnetic radiation back towards said first reflecting unit, both reflecting units providing resonance modes of said electromagnetic radiation within said cavity, wherein an optical path of said beam within said cavity is defined in length by said first and second reflecting unit, a grating arranged within said optical path of said beam reflected by said first reflecting unit, said grating adapted for tuning the wavelength of said beam, wherein said at least one second reflecting unit is rotatable about an axis by at least 360 degrees along a circle path with respect to said grating, said circle path including at least a portion arranged to intersect with said beam, which is redirected by said grating.

Wavelength tunable cavity with rotational movement

A wavelength tunable laser unit has a laser mode selection, and is adapted to provide a laser signal in accordance with one or more laser control parameters. For operating the laser unit, the laser signal is swept in a wavelength range, a laser operation signal indicative of the laser unit's operation during the sweep is received, and the laser operation signal is analyzed for detecting an indication of a mode hop occurred in the generated laser signals during the sweep. At least one correction value is determined based on the detected mode hop indication, and at least one of the one or more laser control parameters, applicable for a next wavelength sweep, is modified based on the determined at least one correction value.

Wavelength tunable laser source with parameter correction

An apparatus and to a method of monitoring an interferometer, comprising the steps of: coupling a first optical signal into the interferometer and into a wavelength reference element, detecting a first resulting interference signal being a result of interference of parts of the first optical signal in the interferometer, detecting a resulting reference signal of the wavelength reference element, the resulting reference signal being a result of interaction of the first optical signal with the wavelength reference element, and comparing the first resulting interference signal with the resulting reference signal to detect a drift of the interferometer, if any.

Method and apparatus for monitoring an interferometer

A method of using at least a part of a cavity for a first and at least one second laser includes providing a first laser beam to the part of the cavity, splitting the first beam into a first and a second part, splitting the first part into a third and a fourth part, splitting the second part into a fifth and a sixth part, superimposing the third and the fifth part in a way causing extinguishing interference, superimposing the fourth and the sixth part in a way causing cumulative interference to provide a first resulting beam, and performing the above elements with at least one second laser beam provided to the same part of the cavity to provide a second resulting beam.

Multiple laser cavity

A laser being tunable in wavelength includes a first reflecting unit and a second reflecting unit, both reflecting units being arranged to at least partially reflect an incident beam of electromagnetic radiation towards each other, an optical path of said beam of electromagnetic radiation within said cavity, which is defined in length by said first and second reflecting unit, a dispersive device, which is arranged, such that a portion of said optical path of said beam of electromagnetic radiation traverses through said dispersive device, wherein said dispersive device comprises a dispersive characteristic representing a functional dependence of an optical path length of said portion with respect to wavelength of said electromagnetic radiation, wherein said optical path length increases with an increasing wavelength of said electromagnetic radiation.

Wavelength tunable laser with dispersive element

A system for matching a optical filter characteristic of a first filter tunable in wavelength with an optical first signal comprises a modulator for modulating at least a part of the first signal with a modulation signal before being applied to the first filter. An analyzing unit derives a control signal for tuning the first filter by analyzing the modulated first signal after passing the first filter in conjunction with the modulation signal.

Self-adjustable tunable filter

An apparatus and method of controlling an optical signal includes superimposing at least one optical reference signal and the optical signal to obtain at least one interference signal having an actual beat frequency, and pre-selecting one or more of the at least one interference signals using a predetermined bandwidth and a filter characteristic that is asymmetric with respect to an actual frequency of the optical signal, to determine a position of the optical signal relative to the at least one optical reference signal.

Controlling an optical source using a beat frequency

A wavelength tunable laser resonator includes first and second resonator end reflectors for reflecting a beam of electromagnetic radiation towards each other, the first and second resonator end reflectors defining a resonator having an optical path with a length, a gain medium for generating and/or amplifying and emitting the beam towards the first and second resonator end reflectors, arranged within the resonator, and a diffractive optical element within the optical path to filter a wavelength of the beam and to focus a portion of the beam towards the gain medium. One of the resonator end reflectors are movable with respect to other optical elements within the resonator for increasing or decreasing the length of the optical path. The diffractive optical element is movable with respect to other optical elements within the resonator for adapting the filtered wavelength to the increase or decrease of the optical path length.

Wavelength tunable laser with diffractive optical element

An optical resonator receives a light beam having a first state of polarization. The resonator comprises a polarization modifying device () and a polarization dependent coupling device () for coupling light having the first state of polarization into a first path and for coupling light having a state of polarization perpendicular to the first state of polarization into a second path. The polarization dependent coupling device () is arranged to receive from a first propagation direction the light beam having the first state of polarization and to couple the light beam from the first propagation direction in the first path to the polarization modifying device (). The polarization modifying device () is arranged for modifying the state of polarization of the light beam before reentering the first path of the polarization dependent coupling device () from a second propagation direction in order to couple into the second path a portion of the light beam traveling into the second propagation direction.

Laser resonator with direction sensitive decoupling

The invention relates to a method of tuning a laser, comprising the steps of: providing a laser beam to an external cavity, the laser beam traveling through material along a path between a cavity end element and a tuning element, the path having an optical path length, selecting at least one mode of the laser by introducing a dispersion element in the path of the laser, rotating the tuning element about a pivot axis theoretically defined by the intersection of the surface planes of the cavity end element, the dispersion element and the tuning element to tune the laser, changing the optical path length of the path in order to at least partly compensate a shift between the real position of the pivot axis and the theoretically defined position.

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Herrenberg, Germany

Wolf Steffens