An imaging probe (102) for use in measuring surface roughness by angular speckle correlation is shown. The imaging probe comprises a first illumination fibre (201) to illuminate a sample location (103) on a surface, and having an input end for coupling of coherent light into the fibre, and an output end cleaved at an angle .sub.1, a second illumination fibre (202) to illuminate the sample location on the surface, and having an input end for coupling of coherent light into the fibre, and an output end cleaved at an angle .sub.2 that is different from .sub.1, and an image transmission system (204) for transmission of a speckle pattern caused by illumination of the sample location on the surface by coherent light from either the first illumination fibre or the second illumination fibre.

Deriving data for calibration or improving the positioning of a computer-controlled machine including a movable carrier for changing the position of a first machine part relative that of second machine part. The carrier is moved to a plurality of carrier positions such that the position of the first machine part relative to that of the second machine part changes for each of said plurality of positions. At each carrier position, a pattern generator attached to the first machine part is illuminated with at least two illuminators such that at least one spatial light pattern is created in space. Position data related to the position of said carrier is recorded and composite images of said at least one spatial light pattern is recorded in at least two different optical configurations of said at least two illuminators, said pattern generator, and at least one camera.

Disclosed are systems and methods to extract information about the size and shape of an object by observing variations of the radiation pattern caused by illuminating the object with coherent radiation sources and changing the wavelengths of the source. Sensing and image-reconstruction systems and methods are described for recovering the image of an object utilizing projected and transparent reference points and radiation sources such as tunable lasers. Sensing and image-reconstruction systems and methods are also described for rapid sensing of such radiation patterns. A computational system and method is also described for sensing and reconstructing the image from its autocorrelation. This computational approach uses the fact that the autocorrelation is the weighted sum of shifted copies of an image, where the shifts are obtained by sequentially placing each individual scattering cell of the object at the origin of the autocorrelation space.

Systems and methods are provided, which use at least two coherent light sources with known phase relations between them, which are configured to illuminate a target with at least two corresponding spots, an optical unit comprising a mask and configured to focus, onto a sensor, interfered scattered illumination from the spots of the target, passing through the mask, to yield a signal, at least one shifter configured to shift a frequency of at least one of the coherent light sources to provide a carrier frequency in the signal, and a processing unit configured to derive a vibration frequency of the target from the sensor signal with respect to the carrier frequency. The vibration frequency of the target is separated from the carrier frequency and speckle disturbances may be attenuated or avoided.

The present disclosure relates to systems and devices configured to determine the distance to objects within a field of view. Namely, at least a portion of the field of view may be illuminated with a coherent light source. Due to interactions between the laser light, the transmission medium, and the object, characteristic laser speckle patterns may be formed. These characteristic laser speckle patterns may be imaged with a camera. Using statistical image analysis, an estimated distance to the objects within the field of view may be obtained. For example, the image frame may be partitioned into a plurality of image segments. An autocorrelation for each image segment of the plurality of image segments may be obtained. A depth map may be obtained based on the autocorrelations.

A system is described, for use in optical measurement of a sample. The system comprising: an illumination unit configured for providing coherent illumination of one or more selected wavelength ranges and directing it onto one or more selected inspection regions of the sample, a collection unit configured for collecting light returning from the inspection region and generating output data comprising a sequence of image data pieces indicative of secondary speckle patterns formed at an intermediate plane in optical path of light collection, a depth resolving module configured for affecting at least one of the illumination unit and the collection unit for determining an association between collected secondary speckle patterns and depth layers of the sample; and a control unit being connectable to said depth resolving module and configured for operating said depth resolving module and for receiving said sequence of image data pieces from the collection unit and processing said sequence of image data pieces by determining correlation functions between at least portions of said secondary speckle patterns associated with corresponding depth layers of the sample, thereby determining one or more parameter variations along depth of the sample.

Systems and methods are provided for vibrations detection in a scene. Systems comprise at least one coherent light source configured to illuminate the scene, an optical unit configured to focus scattered light from the scene onto a pixelated detector, the detector configured to provide pixel intensity signals, and a processing unit configured to analyze the pixel intensity signals over the pixels of the detector to derive a vibration spectrum of elements in the scene that correspond to the pixels. The signal modulation at each pixel may be used to indicate the vibrations of the scene element(s) that corresponds to the pixel(s). Vibration information concerning the scene may be used to direct other methods of vibration measurements, such as speckle interferometry, according to derived vibration images of the scene.

An imaging probe (102) for use in measuring surface roughness by angular speckle correlation is shown. The imaging probe comprises a first illumination fibre (201) to illuminate a sample location (103) on a surface, and having an input end for coupling of coherent light into the fibre, and an output end cleaved at an angle .sub.1, a second illumination fibre (202) to illuminate the sample location on the surface, and having an input end for coupling of coherent light into the fibre, and an output end cleaved at an angle .sub.2 that is different from .sub.1, and an image transmission system (204) for transmission of a to speckle pattern caused by illumination of the sample location on the surface by coherent light from either the first illumination fibre or the second illumination fibre.

Disclosed are systems and methods to extract information about the size and shape of an object by observing variations of the radiation pattern caused by illuminating the object with coherent radiation sources and changing the wavelengths of the source. Sensing and image-reconstruction systems and methods are described for recovering the image of an object utilizing projected and transparent reference points and radiation sources such as tunable lasers. Sensing and image-reconstruction systems and methods are also described for rapid sensing of such radiation patterns. A computational system and method is also described for sensing and reconstructing the image from its autocorrelation. This computational approach uses the fact that the autocorrelation is the weighted sum of shifted copies of an image, where the shifts are obtained by sequentially placing each individual scattering cell of the object at the origin of the autocorrelation space.

There is provided a speckle measurement apparatus to improve accuracy of flow velocity measurement or the like of particulates such as erythrocytes, the speckle measurement apparatus including an imager that captures scattered light images returned from an object to be measured when the object to be measured is irradiated with coherent light as speckle images, and a controller that determines a measurement area that is the same site of the object to be measured in a plurality of the speckle images captured continuously in time series by the imager by incorporating a displacement amount of a relative positional relationship between the object to be measured and the imager.