A microscope comprising a coherent light source producing a coherent light beam, a light beam guide system comprising a beam splitter configured to split the coherent light beam into a reference beam and a sample illumination beam, a sample holder configured to hold a sample to be observed, a sample illumination device configured to direct the sample illumination beam through the sample and into a microscope objective, a beam reuniter configured to reunite the reference beam and sample illumination beam after passage of the sample illumination beam through the sample to be observed, and a light sensing system configured to capture at least phase and intensity values of the coherent light beam downstream of the beam reuniter.

An optical fiber splitter device comprising at least two optical fibers of different lengths is disclosed for partial or complete compensation of the optical path difference between waves interfering to generate a hologram or an interferogram. Various implementations of this fiber splitter device are described in apparatuses for holographic and interferometric imaging of microscopic and larger samples.

Some embodiments are directed to a technique having an off-axis interferometric geometry that is capable of spatially multiplexing at least six complex wavefronts, while using the same number of camera pixels typically needed for a single off-axis hologram encoding a single complex wavefront. Each of the at least six parallel complex wavefronts is encoded into an off-axis hologram with a different fringe orientation, and all complex wavefronts can be fully reconstructed. This technique is especially useful for highly dynamic samples, as it allows the acquisition of at least six complex wavefronts simultaneously, optimizing the amount of information that can be acquired in a single camera exposure. The off-axis multiplexing holographic system of some embodiments provide an off-axis holography modality that is more camera spatial bandwidth efficient than on-axis holography. Moreover, the off-axis interferometric system allows simple simultaneous acquisition of at least six holographic channels, making it attractive for imaging dynamics.

The invention relates to a device, such as a digital holographic microscope, for detecting and processing a first full image of a measurement object, measured with a first offset, wherein an arrangement is provided for generating at least one further full image with at least one offset that differs from the first offset.

A dark field digital holographic microscope and associated metrology method is disclosed which is configured to determine a characteristic of interest of a structure. The dark field digital holographic microscope includes an illumination branch for providing illumination radiation to illuminate the structure; a detection arrangement for capturing object radiation resulting from diffraction of the illumination radiation by the structure; and a reference branch for providing reference radiation for interfering with the object radiation to obtain an image of an interference pattern formed by the illumination radiation and reference radiation. The reference branch has an optical element operable to vary a characteristic of the reference radiation so as to reduce and/or minimize variation in a contrast metric of the image within a field of view of the dark field digital holographic microscope at a detector plane.

A method for three-dimensional imaging of a sample (302) comprises: receiving (102) interference patterns (208) acquired using light-detecting elements (212), wherein each interference pattern (208) is formed by scattered light from the sample (302) and non-scattered light from a light source (206; 306), wherein the interference patterns (208) are acquired using different angles between the sample (302) and the light source (206; 306); performing digital holographic reconstruction applying an iterative algorithm to change a three-dimensional scattering potential of the sample (302) to improve a difference between the received interference patterns (208) and predicted interference patterns based on the three-dimensional scattering potential; wherein the iterative algorithm reduces a sum of a data fidelity term and a non-differentiable regularization term and wherein the iterative algorithm includes a forward-backward splitting method alternating between forward gradient descent (108) on the data fidelity term and backward gradient descent (110) on the regularization term.

A method for defect inspection of a transparent substrate comprises (a) providing an optical system for performing a diffraction process of object wave passing through a transparent substrate, (b) interfering and wavefront recording for the diffracted object wave and a reference wave to reconstruct the defect complex images (including amplitude and phase) of the transparent substrate, (c) characteristics analyzing, features classifying and sieving for the defect complex images of the transparent substrate, and (d) creating defect complex images database based-on the defect complex images for comparison and detection of the defect complex images of the transparent substrate.

Provided is a super-resolution holographic microscope including a light source configured to emit input light, a diffraction grating configured to split the input light into first diffracted light and second diffracted light, a mirror configured to reflect the first diffracted light, a wafer stage arranged on an optical path of the second diffracted light and on which a wafer is configured to be arranged, and a camera configured to receive the first diffracted light that is reflected by the mirror and the second diffracted light that is reflected by the wafer to generate a plurality of hologram images of the wafer.

The invention relates to a free-beam interferometric method for illuminating a sequence of sectional areas in the interior of the light-scattering object. The method makes it possible for the user to select a larger image field and/or a higher image resolution than previously possible with the occurrence of self-interference of the specimen light from a scattering specimen.

An imaging system includes an infrared illuminator, an ultrasonic emitter, a reference wavefront generator, and an image pixel array. The infrared illuminator emits a general illumination emission into a three-dimensional diffuse medium, where a portion of the general illumination emission encounters a voxel within the diffuse medium. The ultrasonic emitter focuses an ultrasonic signal to the voxel to wavelength-shift the portion of the general illumination emission to generate a shifted infrared imaging signal. The reference wavefront generator generates an infrared reference wavefront having a same wavelength as the shifted infrared imaging signal. The image pixel array captures an infrared image of an interference between the shifted infrared imaging signal and the infrared reference wavefront.