A system for passively monitoring a sample is disclosed. The system comprises an optical arrangement, a filtering unit and a detector unit. The optical arrangement is configured for collecting light arriving from a sample, directing the collected light to the filtering unit for filtering based on at least one of spatial and spectral composition and directing the collected light onto the detector unit. The optical arrangement and the detector unit are arranged to provide imaging of collected light from the sample on the detector unit with selected focusing/defocusing level to generate image data pieces comprising speckle patterns formed in the collected light.

A defect detection device 10 is provided with: a laser light source 11 for irradiating laser light to a measurement region R of a surface of an inspection object S; a laser light source control unit 15 for controlling the laser light source so as to cause laser light to be outputted continuously or quasi-continuously for a time longer than a period of vibration generated in the inspection object; an interferometer (speckle shearing interferometer 14) for generating interference light in which reflected light of the laser light reflected in the measurement region and reference laser light emitted from the laser light source 11 interfere; a detector (image sensor 145) for detecting the intensity of the interference light for each point in the measurement region R; a phase shifter 143 for shifting the phase of the reflected laser light or the reference laser light; an integrated intensity pattern determination unit 16 for obtaining an integrated intensity obtained by integrating the intensity for each point over an integration time longer the period of the vibration in three or more phases, the phase being shifted by the phase shifter 143 into three or more different phases; an interference degree distribution generation unit 17 for obtaining the distribution of the degree of interference based on the integrated intensity obtained in each of the three or more phases for each point; and a defect detection unit 18 for detecting a defect in the measurement region R based on the distribution of the degree of interference in the measurement region R.

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.

A vibration measurement device 10 includes an excitation unit (signal generator 11 and vibrator 12) for exciting an elastic wave to an inspection target S, an illumination unit (wavelength stabilized laser beam source 13 and illumination light lens 14) for performing stroboscopic illumination to a measurement region of a surface of the inspection target S using a wavelength stabilized laser beam source 13, a displacement measurement unit (speckle-sharing interferometer 15) for collectively measuring a displacement of each point of the measurement region in the back-and-forth direction by speckle interferometry or speckle-sharing interferometer. By using the wavelength stabilized laser beam source 13, an interference image can be obtained even when the inspection target S has large surface irregularities.

Disclosed herein are systems, methods, and devices for calibrating contrast measurements from laser speckle imaging systems to accurately determine unknown particle motion characteristics, such as flow rate. The calibration stores to memory calibration data, which may include a set of measurements from samples with known particle characteristics and/or estimates of noise, including the effects on contrast arising from undesired signals unrelated to the unknown particle motion characteristics. The calibration data may be accessed and used to correct an empirical measurement of contrast and/or interpolate a value of the unknown particle motion characteristic. The system may include a light source, photodetector, processor, and memory, which can be combined into a single device, such as a wearable device, for providing calibrated flow measurements. The device may be used, for example, to measure blood flow, cardiac output, and heart rate, and can be used to amplify the pulsatile signal.

Speckle contrast method and system that discriminates photons based on their path length in tissue, the method comprising the steps of: directing light from a pulsed light into a sample by optical elements; synchronizing the time between the pulse injection to sample and the detection unit; collecting the photons that have travelled through the sample by optics, and conveying the photons of a single or a limited number of speckles from the sample to one or more detection elements; time-tagging photons thanks to the synchronization of the detector element and/or the time-tagging electronics with the laser pulse emission; estimating each photon time-of-flight by the difference between its time tag and the laser pulse emission; categorizing the detected photons based on the value of the time-of-flight in a certain number of time gates; measuring the speckle contrast.

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.

An electronic device including an SMI sensor may be operated to predict interference in an SMI signal caused by speckle provided by the SMI sensor and operate the SMI sensor based on predicted interference in the SMI signal caused by speckle. Predicting interference in the SMI signal caused by speckle and operating the SMI sensor accordingly may allow for accurate measurement of physical phenomena using the SMI sensor with reduced power consumption.

The invention relates to a method and system for monitoring at least one parameter of an object. There is provided an imaging system for monitoring at least one parameter of movement of a moving object, the system comprises at least one imaging unit comprising an optical transformer configured and operable for applying spatial image space transformation of at least one parameter of movement into geometric relation, by translating different components of six degrees of freedom of movement in a three-dimensional space into a lateral translation; wherein the imaging unit is configured and operable for imaging the moving object on an image plane and generating image data indicative of the moving object in an x-y plane; the imaging system generating motion data indicative of the six degrees of freedom of movement.

A method and a system for photoacoustic inspection of a part are provided herein. The method may include the following steps: photo-acoustically exciting a predetermined position in a predetermined region on a part by pulsed laser illumination, to yield ultrasonic excitation of the part; coherently illuminating a predetermined location in the predetermined region on the part; detecting an illumination scattered from the predetermined location; determining, based on the scattered illumination, a plurality of sequence of two or more temporally-sequential de-focused speckle pattern images, wherein each of the sequences corresponds to one of the predetermined illuminated locations; and determining a set of translations, each determined based on the sequences, wherein each translation in the set is determined based on two temporally-sequential speckle patterns images in the respective sequence.