Abstract: A broadband interferometry for a measurement range extension beyond a coherence length of a light source includes a wavelength tunable laser as the light source outputting a coherence wavelength beam; and an interferometer disposed between the wavelength tunable laser and a target to be measured and including a reference arm, a measurement arm and a device combining a reference beam and measurement mean to produce a combined interference beam, wherein a local oscillation of the reference beam is replicated by a cavity multiplication or cascading optical delayed lines with a fiber optic cavity, and quantifiable optical properties including a wavelength group delay, a chromatic dispersion, a polarization mode dispersion and a model dispersion are inserted into the local oscillation of the reference beam to incrementally quantify the replicated copies of the local oscillation as the number of the delayed copies of the local oscillation increase for extension of a measurement rage to the target.

Abstract: A optical target assembly is disclosed herein. The optical target assembly is movable about orthogonal pitch, yaw and roll axes and includes a reflector, a pitch and yaw angular sensor assembly, and a roll sensor assembly. The reflector is configured to engage a source of laser light. The pitch and yaw angular sensor includes a laser light sensor and an angle detection sensor. The pitch and yaw angular sensor assembly is configured to measure 360 degrees of motion about the pitch and the yaw axes. The roll sensor assembly is configured to measure 360 degrees of motion about the roll axis. The reflector can include an aperture configured to permit a portion of laser light incident on the reflector to pass through the reflector and onto the laser light sensor. The roll sensor assembly can include a roll angle sensor and a roll level sensor coupled to a two-dimensional pendulum.

Abstract: A optical target assembly is disclosed herein. The optical target assembly is movable about orthogonal pitch, yaw and roll axes and includes a reflector, a pitch and yaw angular sensor assembly, and a roll sensor assembly. The reflector is configured to engage a source of laser light. The pitch and yaw angular sensor includes a laser light sensor and an angle detection sensor. The pitch and yaw angular sensor assembly is configured to measure 360 degrees of motion about the pitch and the yaw axes. The roll sensor assembly is configured to measure 360 degrees of motion about the roll axis. The reflector can include an aperture configured to permit a portion of laser light incident on the reflector to pass through the reflector and onto the laser light sensor. The roll sensor assembly can include a roll angle sensor and a roll level sensor coupled to a two-dimensional pendulum.

Abstract: A multi-dimensional measuring system is disclosed wherein a laser-based tracking unit communicates with an optical target on a measurement instrument to obtain position and orientation information about the instrument. The optical target incorporates a plurality of encoders configured to provide a full 360° working range in pitch, yaw and roll. Full working range in pitch and yaw is achieved through the use of a pitch/yaw angular encoder. Full 360° working range in roll is achieved with a combination of a level sensor and a 360° angular encoder, which are fixed to a pendulum so that the level sensor is always aligned to gravity. Use of a slip-ring mechanism ensures the unlimited full working range in roll. The measurement instrument includes a scanner integrated with a probe receptacle adapted to accept a probe assembly to provide the instrument with both a scanning measurement and a probe measurement capabilities.

Abstract: Disclosed herein are interferometric measurement systems and methods. In one exemplary embodiment an interferometric measuring system for measuring the distance to or displacement of an object includes: a light source; an interferometer with a measuring arm and a reference arm; a dispersive medium; and a detector. The interferometer is disposed between the light source and the object. The dispersive medium is arranged to unbalance the dispersion between the measurement arm and the reference arm. The detector is arranged to detect spectrum interference from the interferometer. In one example, the dispersive medium is a chirped fiber Bragg grating. In another example, the dispersive medium is a highly dispersive optical fiber. In one example, the light source is a broadband light source, and the detector includes a spectrometer. In another example, the light source is a wavelength swept laser, and the detector includes a photodetector or a balanced photodetector.

Abstract: A volumetric error compensation measurement system and method are disclosed wherein a laser tracker tracks an active target as the reference point. The active target has an optical retroreflector mounted at the center of two motorized gimbals to provide full 360 degree azimuth rotation of the retroreflector. A position sensitive detector is placed behind an aperture provided at the apex of the retroreflector to detect the relative orientation between the tracker laser beam and the retroreflector by measuring a small portion of the laser beam transmitted through the aperture. The detector's output is used as the feedback for the servo motors to drive the gimbals to maintain the retroreflector facing the tracker laser beam at all times. The gimbals are designed and the position of the retroreflector controlled such that the laser tracker always tracks to a pre-defined single point in the active target, which does not move in space when the gimbals and/or the retroreflector makes pure rotations.

Abstract: A system for accurate determination of target orientation in a laser tracking system. A target aperture is configured to produce spatially distinct laser beam and background images. A processing unit is configured to determine a centroid of the laser beam image position using information collected from detected images, such as laser beam and background images. The laser beam image centroid position is used to determine an accurate target orientation. In one example, a process for determining target orientation includes the steps of collecting a background image passing through a first retro-reflector at a first laser light sensor; 2) collecting a measurement image passing through a second retro-reflector at a second laser light sensor; 3) establishing a common positional reference point for the measurement image and the background image; 4) subtracting the background image from the measurement image based on the common positional reference point.

Abstract: A laser based tracking unit communicates with a target to obtain position information about the target. Specifically, the target is placed at the point to be measured. The pitch, yaw and roll of the target, and the spherical coordinates of the target relative to the tracking unit are then obtained. Then additional information regarding a probe attached to the target reconciled with the above determination to determine a position of a probe tip. The target can be, for example, an active device incorporated into a moveable device such a remote controlled robot.

Abstract: A laser based tracking unit communicates with a target to obtain position information about the target. Specifically, the target is placed at the point to be measured. The pitch, yaw and roll of the target, and the spherical coordinates of the target relative to the tracking unit are the obtained. The target can be, for example, an active device incorporated into a moveable device such a remote controlled robot.