A metrology apparatus for determining a parameter of interest of a structure formed by a lithographic process on a substrate, the metrology apparatus comprising: an illuminator for illuminating the structure; a lens for collecting at least a portion of radiation diffracted from the structure; and an image sensor for receiving and obtaining a recording of the collected diffracted radiation; wherein the illuminator comprises at least one optical fiber for illuminating the structure directly.

Disclosed is a substrate and associated patterning device. The substrate comprises at least one target arrangement suitable for metrology of a lithographic process, the target arrangement comprising at least one pair of similar target regions which are arranged such that the target arrangement is, or at least the target regions for measurement in a single direction together are, centrosymmetric. A metrology method is also disclosed for measuring the substrate. A metrology method is also disclosed comprising which comprises measuring such a target arrangement and determining a value for a parameter of interest from the scattered radiation, while correcting for distortion of the metrology apparatus used.

Additive manufacturing, such as laser sintering or melting of additive layers, can produce parts rapidly at small volume and in a factory setting. To ensure the additive manufactured parts are of high quality, a real-time non-destructive evaluation (NDE) technique is required to detect defects while they are being manufactured. The present invention describes an in-situ (real-time) inspection unit that can be added to an existing additive manufacturing (AM) tool, such as an FDM (fused deposition modeling) machine, or a direct metal laser sintering (DMLS) machine, providing real-time information about the part quality, and detecting flaws as they occur. The information provided by this unit is used to a) qualify the part as it is being made, and b) to provide feedback to the AM tool for correction, or to stop the process if the part will not meet the quality, thus saving time, energy and reduce material loss.

A system for detecting vibrations from a surface is provided. The system includes a coherent light source for projecting a multi-beam pattern onto the surface and an imaging device for mapping a speckle field generated by each spot formed on the surface by the multi-beam pattern to a unique region of an imaging sensor. The system further includes a processor for processing speckle field information received by the imaging sensor and deriving surface vibration information.

Provided is a sample property detecting apparatus including: a wave source configured to irradiate a wave towards a sample; a detector configured to detect a laser speckle that is generated when the wave is multiple-scattered by the sample, at every time point that is set in advance; and a controller configured to obtain a temporal correlation that is a variation in the detected laser speckle according to time, and to detect properties of the sample in real-time based on the temporal correlation, wherein the detector detects the laser speckle between the sample and the detector or from a region in the detector.

A photo-thermal speckle spectroscopy device having an infrared laser, a visible laser, a foam, and a camera. The infrared and visible lasers are focused on the foam, which causes the visible laser to scatter. A camera records the speckle pattern, which shifts when the IR laser is turned on. The related method of photo-thermal speckle spectroscopy is also disclosed.

A first signal is generated with a first light detector in response to an ultrasound signal encountering a first measurement beam. A second signal is generated with a second light detector in response to the ultrasound signal encountering a second measurement beam. The second measurement beam propagates through the sample and the first measurement beam propagates outside the sample.

This lensless imaging system comprises a receiving support configured to receive a sample, a light source configured to emit a light beam illuminating the sample in an illumination direction, the light source including a diode and a diaphragm, the diaphragm being positioned between the diode and the receiving support in the lighting direction, and a matrix photodetector configured to acquire at least one image of the sample, each image being formed by radiation emitted by the illuminated sample and including at least one elementary diffraction pattern, the receiving support being positioned between the light source and the matrix photodetector in the illumination direction.

The system further comprises a light diffuser positioned between the diode and the diaphragm.

Spatial frequency spectra from periodic, aperiodic and quasi-random structures in materials are shown and used to detect differences among objects via internal coding from the spatial frequencies. The method is applied to different grades of human tissues for a new form of histology and pathology, and to detect art forgeries and coding boxes, money and papers and gems. The randomness of material structures on surface and at depths near surface can be detected from the spatial spectrum. In tissue spectral features from normal to different stages of cancer in tissue for ex vivo and in vivo applications can be recognized by different spectral fingerprints content of the spatial frequency. Similarly, the painting for the strokes of artist is different. A new type of instrument is described to analyze materials as a Spatial Frequency Spectrometer.

A method of correcting distortion of an image, including: analyzing, by a processor, an image segment of the image to identify a speckle artifact, the image segment being obtained from a scanning imaging device; determining, by the processor, an aspect ratio of a shape of the speckle artifact; determining, by the processor, a correction factor for the shape of the speckle artifact based on the aspect ratio; and adjusting, by the processor, a dimension of the image segment based on the correction factor.