Abstract: A light meter for measuring photometric quantities includes a telephotometer having a photo detector to receive light energy entering the telephotometer. A light metering valve, for the purpose of providing a variable field of view, is located in the body of the telephotometer generally at the focal plane of the objective lens of the telephotometer. A controller, which includes a digital processor in communication with the photo detector will process information from the photo detector and from a range finder included in the system to output light intensity of a target light source.

Abstract: A device for determining a distance from an object may include a light emitter for emitting an emission light beam, a light receiver for receiving a reception light beam, and an evaluation unit for determining the distance on the basis of a propagation time of the emission and reception light beams. The reception light beam may arise as a result of reflection of the emission light beam at the object. The light receiver may have a reception optical unit comprising a first lens element and a pinhole diaphragm. A light-impermeable element may shade a central region of the reception optical unit in such a way that the reception light beam is incident in the form of a light ring on the pinhole diaphragm. A second lens element, which is substantially hat-shaped in cross section, is arranged between the first lens element and the pinhole diaphragm.

Abstract: A scan sensor emits detection beams for detecting objects in a scanning area within a scanning plane. The position of the scanning plane is changed by pivoting the sensor device in a scanning area, to produce multiple detection planes. Detection points of objects in the surroundings of the sensor device are detected by the detection beams in the detection planes. Lines are extracted from the detection points of a respective detection plan. Measuring points are determined at the intersection points of the lines with one or more predetermined measuring planes. The measuring points in a respective measuring plane are classified into blocks and lines are extracted on a block basis from the measuring points of the blocks generated, as a result of which structures of objects in the measuring planes are determined.

Abstract: According to the invention, the sensitivity of a method for electronic measurement may be improved, carried out by the principle of heterodyne reception with the steps of broadcast of pulsed electromagnetic radiation (ES) with at least one pulse repetition frequency, reception of back-scattered radiation (RS), whereby the back-scattered radiation (RS) is converted into a received signal, mixing of the received signals, determination of at least one time parameter from the at least one output signal, whereby on mixing the received signals at least two pulsed mixed signals are mixed to give at least two output signals and the at least two mixed signals are phase-shifted relative to each other.

Abstract: An adapter and method for through the lens (TTL) laser range sensor probes enables use of a TTL probe of a given exit pupil size to be used with a shared objective lens requiring a entrance pupil size, as entered from the laser range sensor, that is different from the TTL probe exit pupil size. Embodiments of the adapter include optics, such as a first lens and a resolving second lens that expand or contract the TTL laser radiation depending on whether the first lens is a diverging, a negative focal length lens, or a converging, positive focal length lens, and the second lens is converging or diverging, respectively, in a Galilean arrangement. Embodiments also provide a Keplerian arrangement, can function with non-collimated radiation, and can include mirrors to yield a more compact adapter. Additional embodiments include at least one adjustable lens element between the first and second lenses, the at least one adjustable lens element being connected to an actuator for movement along the optical path.

Abstract: Embodiments of the invention comprise an apparatus for use with a laser range finder configured to direct a laser beam toward a scene to measure the distance to a target in the scene and having a range finder display for displaying data, including data that is indicative of the distance to a target, wherein the apparatus comprises a protective housing, a camera module in the housing, the camera module including a lens mounted in a front end portion of the housing, and a light path through the lens to image sensor, an image sensor operatively connected to the camera module for receiving images acquired by the camera module, electronic memory for selectively storing data of images from the image sensor, circuitry for controlling the operation of the image sensor and the memory, a camera display in the housing operatively connected to the image sensor for receiving the image data and providing a visual display of the image, and a switch for storing image data in the memory.

Abstract: Dual mode depth imaging system and method is provided, the system comprising a first and second image sensors and a processor able to switch between a first mode of depth imaging and a second mode of depth imaging according to at least one predefined threshold. The method comprising providing depth sensing by Time of Flight if the distance of the sensed object from the camera is not below a first threshold and/or if a depth resolution above a second threshold is not required, and providing depth sensing by triangulation, if the distance of the sensed object from the camera is below the first threshold and/or if a depth resolution above the second threshold is required.

Abstract: The invention proposes a sensor array having a plurality of sensor devices comprising a source of electromagnetic radiation, a receiver for the electromagnetic radiation and a control device, the control device being designed to use the source to emit electromagnetic radiation and being designed to determine a distance covered by electromagnetic radiation, which is emitted by the source, from a reflection surface of an object to the receiver by evaluating the reflected radiation. According to the invention, the sensor devices of the plurality of sensor devices operate at different frequencies or using time-division multiplexing. The invention also proposes a sensor device for a sensor array, the control device being designed to measure the distance at different frequencies or using time-division multiplexing.

Abstract: The invention relates to an electro-optical measuring device, in particular a hand-held device (10) for contactless distance measurement, comprising an optical transmission path (28), which has a first optical axis (72) and which has at least one optical transmitter (20) for emitting a measurement signal, and also comprising a reception path (29) having a second optical axis (74), which is spaced apart from the first optical axis (72), with at least one reception optic (32) for focusing a measurement signal in the direction of a receiver (26), and also comprising an optical near range element (60) for parallax compensation. It is proposed that the near range element (60) be embodied rotationally symmetrically with respect to the second optical axis (74).

Abstract: A method for measuring the distance of an object is provided that includes irradiating a plurality of light beams having predetermined wavelengths and then in a first round, picking up an image under irradiation of the plurality of light beams and in another round picking up the image without irradiation using a camera. The difference of the image between the first and other round is fed to an observation region part and to an irradiation angle computing part and then the distance to the object is computed.

Abstract: A lidar and digital camera system collect data and generate a three-dimensional image. A lidar generates a laser beam to form a lidar shot and to receive a reflected laser beam to provide range data. A digital camera includes an array of pixels to receive optical radiation and provide electro-optical data. An optical bench passes the laser beam, reflected laser beam, and optical radiation and is positioned to align each pixel to known positions within the lidar shot. Pixels are matched to form a lidar point-cloud which is used to generate an image.

Abstract: A system for testing an optical surface includes a rangefinder configured to emit a light beam and a null assembly located between the rangefinder and the optical surface. The null assembly is configured to receive and to reflect the emitted light beam toward the optical surface. The light beam reflected from the null assembly is further reflected back from the optical surface toward the null assembly as a return light beam. The rangefinder is configured to measure a distance to the optical surface using the return light beam.

Abstract: The invention relates to a method for measurement of a line (S), in particular, an optical distance measurement method, whereby an input means (24,42) of a distance measuring device (20,22) is operated, which triggers a measuring sequence of distance measurements, during which individual measurements (10-16) of distances from the distance measuring device (20,22) triggered by the distance measuring device (20,22) are carried out perpendicular to the line (s) for measurement. According to the invention, at least one maximum value (10,16) and at least one minimum value of the distances are determined from the measuring sequence and the length of the line (s) determined from the at least one maximum value (10,16) and the at least one minimum value (13). The invention further relates to a distance measuring device (20,22), in particular, a hand-held measuring device for carrying out said method.

Abstract: A light beam receiver includes a plurality of light beam detector elements, a plurality of integrator circuits that receive signals from the light beam detector elements, and a signal integral limiting integration time controller that is in communication with at least two of the integrator circuits so that an analysis of the light beam reception is determined. One embodiment provides a self-calibration function, using a plurality of light beam detector elements that generate output signals when receiving a light beam upon the light beam detector elements, an evaluation/control circuit that receives the output signals and is configured to substantially determine a position where the light beam impacts on the light beam detector elements, and at least one calibration light source that emits at least one light pulse that is coupled to the light beam detector elements. The light beam receiver performs a self-calibration function using the calibration light source.

Abstract: A method for calculating a distance to an object is provided. In this method, whether luminances received by at least one light receiving elements of a plurality of light receiving elements are equal to or higher than a predetermined value is determined. When luminances received by at least one light receiving elements are equal to or higher than a predetermined value, whether the luminances change in a time-series manner or not is determined. When the luminances change in a time-series manner, information is acquired from the time-series change. Then, a size of a light receiving region is detected based on a ratio of a light receiving element having received luminance with a predetermined value or more to the plurality of light receiving element. Based on the size of the light receiving region and the acquired information, the distance to the object is calculated.

Abstract: Rapid calibration of a TOF system uses a stationary target object and electrically introduces phase shift into the TOF system to emulate target object relocation. Relatively few parameters suffice to model a parameterized mathematical representation of the transfer function between measured phase and Z distance. The phase-vs-distance model is directly evaluated during actual run-time operation of the TOF system. Preferably modeling includes two components: electrical modeling of phase-vs-distance characteristics that depend upon electrical rather than geometric characteristics of the sensing system, and elliptical modeling that phase-vs-distance characteristics that depending upon geometric rather than electrical characteristics of the sensing system.

Abstract: In a laser receiver receiving a laser beam from a laser transmitter and a laser receiving system composed of a plurality of laser receivers, a plurality of photo devices are arranged on an acceptance surface so that acceptance angles of the laser beam thereof are mutually different in order to detect distances between an acceptance position of a center point of a received laser beam on an acceptance surface and a reference point and an elevation angle of the received laser beam from a reference surface. Also, distance detection means respectively compare acceptance levels of the photo devices detected by the level detection means with thresholds, thereby detecting distance between the center point of the laser beam and the reference point of the acceptance surface by combination of comparison results thereof.

Abstract: A laser device and method capable of one or more dimensional absolute distance measurements and/or surface scanning and/or coordinate measurements of a moving external retroreflector or other moving target surfaces without using an incremental interferometer.

Abstract: Methods for using spectrally separated light pulses to collect more LIDAR information are presented. In one embodiment, a monochromatic pulse is transmitted to collect range information and a white pulse is transmitted a short time afterwards to collect spectral responsivity information or color of the target. In another embodiment, the white light pulse is used to collect both range and spectral responsivity information of the target. In another embodiment, the spectral separated laser is spatially spread in order to collect range information over more than one point at a time.

Abstract: A radar system for use in a vehicle includes a transmission function for transmitting a transmission wave at a predetermined interval, a redirection function having a plurality of redirection planes for redirecting the transmission wave at least twice in a successive manner in a same direction, a reception function for outputting a reception signal based on a reception of a reflected wave that corresponds to the transmission wave, and an integration function for outputting an integration signal upon integrating a plurality of the reception signals that correspond to the transmission waves redirected in the same direction.

Abstract: Ladar systems and methods are provided. One embodiment is a ladar system comprising: a chirp generator for generating a chirped waveform; a laser for transmitting a light signal toward a target, the light signal being modulated by the chirped waveform; and a photon-counting sensor for receiving a temporally-modulated photon stream corresponding to the modulated light signal being reflected from the target and toward the ladar system, the photon-counting sensor gated relative to the chirped waveform.

Abstract: A device and a method for measuring the sizes of a remote object, for example, concrete crack, without using a high-place work vehicle or a ladder. An optical apparatus (e.g. a measuring device (10) ) used for this purpose is provided with a telescope (16) having a reticule plate (46) . The reticule plate (46) is provided with a plurality of reference scales (52) used for comparison with the size (W) of the image (C?) of an object (C) projected onto the reticule plate (46). The size of the object can be measured using the size of the object image measured with the reference scales (52) and a distance (a distance from a reference point P0 a to the object) measured with a distance measuring unit (20) of the optical apparatus.

Abstract: When the geometric distance L from the body of an interferometer to a target 110 is accurately measured from distance measurement values D1, D2 which are obtained by a lightwave interferometric measurement using laser beams of plural wavelengths ?1, ?2, while correcting the refractive index of air, the wavelengths of the laser beams are measured by using an optical comb generated from an optical comb generator 104. In this case, the oscillation wavelength of a variable wavelength laser 101 is measured by using the optical comb, and a feedback control is performed, whereby laser beams of plural predetermined wavelengths are obtained, or a variable wavelength laser is caused to oscillate at plural arbitrary wavelengths to obtain plural distance measurement values. The wavelengths (frequencies) of laser beams when the respective distance measurement values are obtained are measured by the optical comb, and used in calculation of the geometric distance.

Abstract: A visual sensor for generating an array of binarized feature signals based on a visual field is provided. The visual sensor comprises an array of photoreceptor circuits capable of generating photoreceptor signals based on the visual field, an array of feature detectors capable of generating feature signals based on the photoreceptor signals, and a reconfigurable binary generator array capable of generating binarized feature signals based on the feature signals.

Abstract: A light detection system duplicates the dynamic range of low intensity non-cooperative targets for high intensity cooperative targets. Both dynamic ranges of return light pulses are supported at the same time. In one embodiment, two beam splitters are used to reduce the intensity of reflected light that is received from high intensity sources to levels that can be accurately ranged. Ambiguity between the two paths is resolved by using an additional detector. Alternatively, one beam splitter is used to reduce the intensity of reflected light that is received from high intensity sources to levels that can be accurately ranged. The beam splitter system increases the effective dynamic range of the detection and ranging system passively without any need to reconfigure the system.

Abstract: A surveying instrument performs tracking of a target by controlling an orientation of a measuring unit relative to the target in two different angular directions. The control in one angular direction is based on detected light intensities which are modulated according to a first time pattern, and control of the orientation in the other angular direction is based on detected light intensities modulated according to a second time pattern just different from the first time pattern.

Abstract: Apparatuses and methods for gathering data describing a surface are disclosed. The apparatuses transmit pulses of light at a high rate using one or more fiber lasers. Examples of such apparatuses include laser ranging systems, such as light detection and ranging (LIDAR) systems, and laser scanners. Data received from the apparatus by a data processing unit can be used to create a data model, such as a point cloud, digital surface model or digital terrain model describing the surface. The surface can be the surface of terrain and/or objects, for example. Use of the fiber laser results in many advantages, such as improved vertical surface discrimination, increased pulse rate, safety benefits, as well as other advantages.

Abstract: 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.

Abstract: According to the invention, high precision distance measurement may be carried out by the broadcast of pulsed electromagnetic radiation (ES) with at least two pulse repetition frequencies, whereby the pulse repetition frequencies are selected such that the corresponding pulse separations do not have a common multiple in the range of the order of magnitude of a maximum external measurement range. The radiation is hence transmitted both to a target for measurement over the measurement path outside the device and also over a reference path inside the device, whereby the radiation (IS) passing along the reference path defines at least one start pulse and the radiation (ES) passing along the measurement path defines at least one stop pulse.

Abstract: A system for measuring distance to an optical surface includes a range finder for transmitting a beam toward the optical surface, and a ring mirror disposed between the range finder and the optical surface. The ring mirror has (a) a circumferential reflecting surface for reflecting a portion of the transmitted beam back to the range finder, and (b) a central aperture for passing another portion of the transmitted beam toward the optical surface. The circumferential reflecting surface is effective in providing a zero reference point for the range finder. The central aperture is effective in passing the transmitted beam to the optical surface for sequentially addressing the optical surface at different locations on the optical surface. The transmitted beam may be steerable for (a) providing the zero reference point circumferentially about the reflecting surface, and (b) providing sequential addresses to locations on the optical surface.

Abstract: In a method and a measuring device (10) for measuring an absolute distance value corresponding with a range (9) between a measuring device (10) and a target (8), wherein for measuring the absolute distance value a number of individual measuring steps are performed with an absolute distance meter (1), a distance variation between the measuring device (10) and the target (8) is also measured with a relative distance meter (2) at least approximately simultaneously with these individual measuring steps and the distance variation is taken into account as the absolute distance is being determined. Preferably an iterative method comprising several sampling steps is used for measuring the absolute distance, e.g. according to the Fizeau method, wherein an output value (A) is generated from an input value (fn, fn+1, fn+2, . . . ) and measured in each sampling step. The output value (A) is dependent on the input value (fn, fn+1, fn+2, . . . ) and on the distance.

Abstract: The invention relates to a mobile measurement system, comprising at least one apparatus (16) for optical distance measurement having at least one transmission unit having a light source for emitting modulated, optical radiation (24) in the direction of a target object (26), and having a reception unit for receiving the optical measurement radiation (28) returning from the target object (26), and having an actuation appliance (18, 20, 60) having at least one memory element (42) for holding data, the apparatus (16) for optical distance measurement being connected to the actuation appliance (18) via an interface (31) for the purpose of data transmission. The invention proposes that the interface (31) be a radio interface. The invention also relates to a method of operation for such a mobile measurement system in which the connection setup between the appliances takes place automatically.

Abstract: A data processing system, computer implemented method, and computer program product code determines distances to an object. Computer generated environments can be calculated therefrom. A light source is focused on an object at an unknown distance from an imaging device, creating a point-of-light. The imaging device, focused on a focal plane at a second location, records an out-of-focus image of the point-of-light at the first distance. From the out-of-focus image, the diameter of a circle of confusion for the point-of-light is identified. The distance between the object and the imaging device is then calculated from the circle of confusion.

Abstract: A target having a reflective part for a laser beam is located at the measuring object position of a bridge girder in such a way that the reflective part includes with respect to the displacement measuring direction and a laser rangefinder is located at the pier. A laser beam projected from the laser rangefinder along the longitudinal direction of the bridge girder impinges on the reflective part and the reflected light of the laser beam returned from the reflective part in the direction generally parallel with the incident direction is received by the laser rangefinder so as to detect variation in the distance from the laser rangefinder to the laser beam reflecting position of the reflective part. Displacement of the bridge girder in the displacement measuring direction is measured utilizing correlation between the detected variation and the displacement of the measuring object position in the displacement measuring direction.

Abstract: The radar apparatus includes a transmit/receive section having a function of emitting a transmission wave, receiving the transmission wave reflected from a reflecting object, and outputting a reception signal having a signal level depending on the intensity of the received transmission wave, a control section controlling the transmit/receive section to transmit the transmission wave a predetermined number of times in the same direction, an integrating section successively integrating the reception signal successively outputted from the transmit/receive section to thereby successively form an integrated signal while the transmit/receive section repeatedly emits the transmission wave in the same direction, and a detector section judging whether or not the integrated signal enables detection of the reflecting object.

Abstract: Performance of pixel detectors in a TOF imaging system is dynamically adjusted to improve dynamic range to maximize the number of pixel detectors that output valid data. The invention traverses the system-acquired z depth, the brightness, and the active brightness images, and assigns each pixel a quantized value. Quantization values encompass pixels receiving too little light, normal light, to too much light. Pixels are grouped into quantized category groups, whose populations are represented by a histogram. If the number of pixels in the normal category exceeds a threshold, no immediate corrective action is taken. If the number of pixel receiving too little (or too much) light exceeds those receiving too much (or too little) light, the invention commands at least one system parameter change to increase (or decrease) light reaching the pixels. Controllable TOF system parameters can include exposure time, common mode resets, video gain, among others.

Abstract: A method for calibrating an optical reflectance proximity sensor and then measuring proximity in a repeating cycle or on demand, the sensor including one or more wavelength transmitting diodes, one or more wavelength receiving diodes, an ambient correction circuit, and a comparator circuit, and further teaching steps for powering on the sensor, canceling the ambient signal during a calibration period, transmitting wavelengths to and receiving reflectance from an object in the path of the transmitted wavelengths, and measuring a reflectance pulse width and comparing the value to a preset value to determine proximity.

Abstract: A method, computer program product, and apparatus for making and displaying measurements based upon multiple 3D range data sets obtained using a 3D rangefinder device. At least a first and a second 3D range data sets are provided. A 3D transformation is computed therebetween. The first 3D range data set is represented as a first displayed image and the second 3D range data set is represented as a second displayed image. At least two features are identified within the first and second displayed images respectively. A measurement is computed based on at least the first feature and the second feature utilizing the 3D transformation between the first and second 3D range data sets. The computed measurement may be displayed within at least one of the first displayed image and the second displayed image.

Abstract: The present invention provides a distance measuring device, which comprises a light projecting unit for projecting a distance measuring light (22) to an object to be measured, a reference reflection unit (55) provided relatively movable and arranged at a known position so as to traverse the projected distance measuring light, a photodetection unit (7) for receiving a reflection light from the object to be measured as a reflected distance measuring light (22?) and a reflection light from said reference reflection unit as an internal reference light (22?), and a control arithmetic unit (15) for calculating a distance to the object to be measured based on a photodetection signal relating to the reflected distance measuring light and based on a photodetection signal relating to the internal reference light.

Abstract: In a distance/speed meter, first and second semiconductor lasers emit parallel laser light beams to a measurement target. A first laser driver drives the first semiconductor laser such that the oscillation interval in which at least the oscillation wavelength monotonically increases repeatedly exists. A second laser driver drives the second semiconductor laser such that the oscillation wavelength increases/decreases inversely to the oscillation wavelength of the first semiconductor laser. First and second light-receiving devices convert optical outputs from the first and second semiconductor lasers into electrical signals. A counting unit counts the numbers of interference waveforms generated by the first and second laser light beams and return light beams of the first and second laser light beams.

Abstract: The invention proposes a sensor array having a plurality of sensor devices comprising a source of electromagnetic radiation, a receiver for the electromagnetic radiation and a control device, the control device being designed to use the source to emit electromagnetic radiation and being designed to determine a distance covered by electromagnetic radiation, which is emitted by the source, from a reflection surface of an object to the receiver by evaluating the reflected radiation. According to the invention, the sensor devices of the plurality of sensor devices operate at different frequencies or using time-division multiplexing. The invention also proposes a sensor device for a sensor array, the control device being designed to measure the distance at different frequencies or using time-division multiplexing.

Abstract: TOF system shutter time needed to acquire image data in a time-of-flight (TOF) system that acquires consecutive images is reduced, thus decreasing the time in which relative motion can occur. In one embodiment, pixel detectors are clocked with multi-phase signals and integration of the four signals occurs simultaneously to yield four phase measurements from four pixel detectors within a single shutter time unit. In another embodiment, phase measurement time is reduced by a factor (1/k) by providing super pixels whose collection region is increased by a factor “k” relative to a normal pixel detector. Each super pixel is coupled to k storage units and four-phase sequential signals. Alternatively, each pixel detector can have k collector regions, k storage units, and share common clock circuitry that generates four-phase signals. Various embodiments can reduce the mal-effects of clock signal transients upon signals, and can be dynamically reconfigured as required.

Abstract: A door sensor system (90) for detecting a target object (56) in and/or near a door comprising a door opening (96), and at least one movable door element (76, 76-1, 76-2, 76-3, 76-4), the system comprising at least one light scanner device (10) which is capable of measuring optically the distance to a target to make such a measurement over a given scan angle at regular intervals by deflecting the light with moving mirrors, and which generates at least one vertical plane of detection.

Abstract: The present invention provides apparatuses and methods for determining spatial information of a workpiece surface positioned in a predetermined coordinate system. Apparatuses and methods of the present invention can be used to determine one or more coordinates of one or more measurement locations of a workpiece within a predetermined coordinate system. Such coordinates can be used to define points, lines, and/or surfaces of the workpiece within the coordinate system. In one exemplary application, apparatuses and methods of the present invention can be used to determine spatial information of surfaces of head suspensions or head suspension assemblies such as those that are generally utilized in dynamic storage devices such as magnetic disk drives. Such spatial information can be used to determine z-height and/or static attitude, for example.

Abstract: A dual mode LADAR/SAL apparatus is disclosed. In one aspect, the apparatus includes a gimbal capable of scanning in azimuth and in elevation and a sensor mounted on the gimbal. The sensor includes a telescope, a LADAR optical path, and a SAL optical path. The telescope defines an exit pupil through which the sensor collects reflected light. The sensor further includes means for directing light received through the telescope to the LADAR optical path in a first position and to the SAL optical path in a second position such that the SAL optical path receives the collected light from the exit pupil of the telescope. The means may be, for example, a mirror. In a second aspect, an apparatus includes a gimbal capable of scanning in azimuth and in elevation, and a sensor mounted on the gimbal. The sensor includes a telescope defining an exit pupil through which the sensor collects reflected light.

Abstract: A surveying instrument for projecting a distance measuring light to an object to be measured and for measuring a distance from a reflected light, comprising at least an image pickup unit for picking up an image of a spreading range of the distance measuring light, and a control unit for performing edge extraction from the image captured by the image pickup unit and for judging whether there is an edge or not within the spreading range.

Abstract: The present invention relates to a surveying instrument for measuring the distance to a target to be measured, a horizontal angle, and a vertical angle by use of reflected light. An imager can be connected to the surveying instrument. In addition, an arithmetic processing means can determine a three-dimensional position of a plane part by determining from at least three measuring points an equation that includes the plane part as the target to be measured, and then by associating digital image data to which the plane part belongs with the equation so that the plane part is identified.

Abstract: An external cavity laser has an external cavity that is formed between a target surface and a laser diode facet located farthest from the target surface. A chromatic dispersive element is disposed in the external cavity, and focuses light from the laser diode such that one wavelength is focused at a focal spot on the target surface. Light reflected from the focal spot on the target surface is the predominant wavelength coupled back into the laser waveguide, which provides a feedback signal that determines the oscillation wavelength of the laser diode. The laser diode therefore outputs a well-defined wavelength of light which corresponds to the distance between the chromatic dispersive element and the target surface.

Abstract: A light wave rangefinder includes a light transmitting optical system for directing a laser pulse at a target, and a light receiving optical system for receiving reflected light from the target, including a Geiger-mode avalanche photodiode (APD) array and a non-imaging optical device. The non-imaging optical device is positioned between the received reflected light and the APD array, and is configured to uniformly distribute the received reflected light across the APD array. The APD array is uniformly illuminated by a single received reflected laser pulse, producing a plurality of Geiger-mode avalanche events.

Abstract: In a laser detecting and ranging apparatus in which a light signal is intensity-modulated with a modulating frequency consisting of a frequency in the microwave band for thereby detecting a Doppler frequency relating to the modulating frequency, high reception sensitivity is realized.