Abstract:
Methods and apparatuses are described for frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR). Examples are provided where high-closed-loop bandwidth, active feedback applied to laser frequency chirps may provide increases in the free-running laser coherence length for long-range FMCW distance measurements. Examples are provided that use an asymmetric sideband generator within an active feedback loop for higher closed-loop bandwidth. Examples of using a single shared reference interferometer within multiple active feedback loops that may be used for increasing the coherence length of multiple chirped lasers are described. Example calibrators are also described.
Abstract:
Transmitter signals are modulated with one or more codes which may represent a pulse even though the code(s) are not shaped as pulses. The code(s) may be generated by defining a pulse by its Fourier components, and then adding random phases to the Fourier components. A time-domain signal may then be created, which may serve as the code to be modulated on a carrier wave. Upon reflection of the transmitter signal, the received signal may be processed by a receiver to recover the pulse. The time-of-flight of the transmitter signal can then be determined, enabling distance measurements to be made.
Abstract:
An optical arrangement, method and measurement system are disclosed. The arrangement includes a first input to receive a first beam from a frequency swept laser, a second input to receive a second beam from a fixed frequency pump laser source. A non-linear optical artefact receives and intermodulates the first and second beams to generate a third beam, the third being an inverted copy of the first beam mirrored relative to the fixed frequency of the pump laser source. A selective combining element outputs the first and third beams. The non-linear artefact or one or both of the lasers is selected or configured such that the optical frequency separation of the first and second beams satisfies the coherence length condition of the non-linear artefact.
Abstract:
Es wird eine Messvorrichtung (1) zur optischen Entfernungsmessung vorgestellt. Die Messvorrichtung (1) weist eine Sendeeinrichtung (3), eine Empfangseinrichtung (7), eine Modulatoreinrichtung (5), eine Auswerteeinrichtung (9) und eine Kalibriereinrichtung (11) auf. Die Sendeeinrichtung ist dabei zum Aussenden eines ersten Signals (15) auf ein Objekt (13) zu ausgeführt. Die Modulatoreinrichtung (5) ist dabei zum Modulieren des ersten Signals (15) ausgeführt. Die Empfangseinrichtung (7) ist ausgeführt, ein zweites Signal (17) zu detektieren. Die Auswerteeinrichtung (9) ist zum Empfangen und Auswerten des zweiten Signals (17) ausgeführt. Die Kalibriereinrichtung (11) ist ausgeführt, die Messvorrichtung (1) bei eingeschalteter Modulatoreinrichtung (5) und bei unterhalb eines vorgebbaren Leistungsschwellenwerts betriebener Sendeeinrichtung (3) zu kalibrieren.
Abstract:
TOF system optical power is augmented using auxiliary optical emitter unit(s) that may be wireless (WOE), or plug-wired (PWOE). WOE units sense emitted TOF system optical energy Sout and emit optical energy Sout-n preferably dynamically synchronized in frequency and in phase to Sout as received by WOE. Each WOE includes at least one optical sensor to detect Sout, and internal feedback ensuring that frequency and phase of WOE emitted Sout-n optical energy are dynamically synchronized with frequency and phase of TOF emitted Sout optical energy. PWOE units need no internal feedback but are calibrated by TOF system to cause a close match between frequency and phase of the PWOE-emitted optical energy with what would be emitted by the TOF system primary optical source. If PWOE(s) are used in isolation, delay difference between PWOE and the TOF primary optical energy source can be software-compensated.
Abstract:
Die Erfindung betrifft eine Vorrichtung zur ortsaufgelösten Objektentfernungsbestimmung mit einer frequenzverschoben rückgekoppelten Strahlungsquelle zur Objektbestrahlung mit entfernungsbestimmungsnutzbarer Strahlung und einem positionsempfindlichen Objekterfassungssensor. Hierbei ist vorgesehen, daß die frequenzverschoben rückgekoppelte Strahlungsquelle zur Objektbestrahlung mit einem Mittel zur Emissionsfrequenzkomponentenschwebungsintensitätserhöhung und der positionsempfindliche Objekterfassungssensor zur Erfassung der Schwebungsintensität vom Objekt und nicht-vom Objekt einlaufender Strahlung ausgebildet ist.
Abstract:
This invention provides a method and an optical system for sensing and controlling the frequency for a laser with respect to an optical cavity and for sensing and controlling the length difference of interferometer paths in a two beam interferometer. A misalignment is introduced in the incident laser radiation to produce a fundamental mode (TEM00) in the cavity or interferometer and the reflection of at least one higher order mode (TEM01). A split photodetector (10) allows the interference between these two modes to be measured separately by detecting two spatially distinct portions of the single reflected beam. An error signal indicative of the difference between the fundamental mode frequency and the cavity resonant frequency is obtained by substracting the outputs from the two parts of the photodetector.
Abstract:
An apparatus is provided for 3D imaging of an object comprising a scanning light beam encoded with position data corresponding to the spatial position of the scanning light beam, and an imaging system that images localized surface areas of the object illuminated by the scanning light beam, which imaging system records the position data coded into the scanning beam so that three spatial coordinates of the localized surface areas imaged are determinable using the recorded position data.
Abstract:
A detection system for detecting the position of an object on a movable member and particularly for detecting the position of a ball in a moving roulette wheel (1, 4) comprises a light source (13, 14, 15) to emit visible light which is modulated. A sensor (16) is provided to receive reflections by the ball and the moving roulette wheel (1, 4) of said emitted modulated light. The reflections are analysed by appropriate means to determine the position of the member (4) and the location of the object in relation thereto. The light source (13, 14, 15) may transmit white light and the sensor (16) detect specific similarly modulated wavelengths, which are predetermined dependent on the relative chrominance of the numbers ring and the pockets ring (6) of the wheel (1, 4), and the object. Alternatively, the light source (13, 14, 15) may transmit light of specific wavelengths which are predetermined dependent on the relative chrominance of the numbers ring and the pockets ring (6) of the wheel (1, 4), and the ball, and the sensor (16) may detect similarly modulated wavelengths over the broadband visible light range.