An apparatus and method for displaying holograms. A compact and self-contained lighting system for a display hologram, which can produce high quality images and which is substantially insensitive to stray light.

An optical reflective device referred to as a skew mirror, having a reflective axis that need not be constrained to surface normal, is described. Examples of skew mirrors are configured to reflect light about substantially constant reflective axes across a relatively wide range of wavelengths. In some examples, a skew mirror has substantially constant reflective axes across a relatively wide range of angles of incidence. Exemplary methods for making and using skew mirrors are also disclosed. Skew mirrors include a grating structure, which in some examples comprises a hologram.

A photorefractive (PR) polymer composite (310) is provided that includes a charge transporting polymer (CTP) matrix (311) and a photosensitizer (312) comprising a quantum dot (QD) material (314) with a first band gap (315) coupled to a nanoparticle material (317) with a second band gap (316) greater than the first band gap. The photosensitizer (312) is configured to generate a plurality of free charges (318) and to transfer the free charges to the CTP matrix (311) in response to an incident photon (320) on the PR polymer composite (310). An apparatus (500) is also provided, for writing holograms of 3D perspective views of an object from different directions within the PR polymer composite (310). A method (600) is also provided for forming the PR polymer composite.

An image capturing apparatus (500) capable of performing three-dimensional tomography of an object by digital holography, includes a splitting element (502) which splits a light beam emitted from a light source into an object light beam and a reference light beam, an illumination system (503) which controls a plurality of object light beams that are generated from the object light beam and that move in directions different from each other to be incident on the object simultaneously, a composite element (507) which causes the plurality of object light beams to interfere with the reference light beam, an image sensor (508) which acquires hologram generated by interference of each of the plurality of light beams with the reference light beam, and a controller (509) which controls the illumination system so that the plurality of object light beams interfere with each other on the image sensor.

In an embodiment a hologram recording system includes an optical system configured to provide first and second beams of electromagnetic radiation, the optical system having a first lens configured to interact with the first beam, a photosensitive recording medium configured to receive the first and second beams and record an interference pattern formed by the first and second beams and an actuation system configured to move a component of the optical system to adjust a position of the first beam relative to the first lens and thereby control an angle of incidence of the first beam at the photosensitive recording medium, wherein the first lens is configured to interact with the second beam, and wherein the actuation system is configured to move a second component of the optical system to adjust a position of the second beam relative to the first lens and thereby control an angle of incidence of the second beam at the photosensitive recording medium.

An optical reflective device referred to as a skew mirror, having a reflective axis that need not be constrained to surface normal, is described. Examples of skew mirrors are configured to reflect light about a constant reflective axis across a relatively wide range of wavelengths. In some examples, a skew mirror has a constant reflective axis across a relatively wide range of angles of incidence. Exemplary methods for making and using skew mirrors are also disclosed. Skew mirrors include a grating structure, which in some examples comprises a hologram.

Imaging apparatus and methods using diffraction-based illumination are disclosed. An example apparatus includes a diffraction grating to redirect light from a light source toward a sample to thereby illuminate the sample. The example apparatus also includes an image sensor to detect a diffraction pattern created by the illuminated sample.

The techniques, apparatus, material and systems are described for a portable camera device which can be attached to the camera port of a conventional transmission or reflection microscope for complex wave front analysis. At least one holographic element (BS, grating) splits the beam (s) containing the sample information in two beams (r,o) and filters (r, o) them. The proposed invention has a relaxed alignment sensitivity to displacement of the beam coming from the microscope. Besides since it compensates the coherence plane tilt angle between reference and object arms, it allows for creating high-visibility interference over the entire field of view. The full-field off-axis holograms provide the whole sample information.

An optical reflective device referred to as a skew mirror, having a reflective axis that need not be constrained to surface normal, is described. Examples of skew mirrors are configured to reflect light about a constant reflective axis across a relatively wide range of wavelengths. In some examples, a skew mirror has a constant reflective axis across a relatively wide range of angles of incidence. Exemplary methods for making and using skew minors are also disclosed. Skew mirrors include a grating structure, which in some examples comprises a hologram.

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.