A lensless holographic imaging system having a holographic optical element includes: a coherent light source for outputting a first light beam and a second light beam, wherein the first light beam irradiates a first inspection plane to form first object-diffracted light; a light modulator for modulating the second light beam into reading light having a specific wavefront; a multiplexed holographic optical element, wherein the first object-diffracted light passes through the multiplexed holographic optical element, and the reading light is input into the multiplexed holographic optical element to generate a diffracted light beam as system reference light; and an image capture device for reading at least one interference signal generated by interference between the first object-diffracted light and the system reference light. The lensless holographic imaging system has a relatively small volume and relatively high diffraction efficiency.

Embodiments of this application provide example holographic recording media, holographic polymer materials, methods for preparing holographic polymer materials, and display devices. An example holographic recording medium includes a first-order crosslinked network, a photoinitiator, and a second-order monomer. The first-order crosslinked network provides a mechanical support for the holographic recording medium. The second-order monomer includes a monomer with a free radical reactivity. The photoinitiator is used to initiate polymerization of the second-order monomer. The holographic recording medium includes at least one of an ester group (I), a urethane group (II), a carbamido group (III), an allophanate group (IV), or an amide group (V). Groups linked to the ester group (I), the urethane group (II), the carbamido group (III), the allophanate group (IV), and the amide group (V) are separately selected from at least one of the following: alkyl, alkoxy, alkenyl, or aryl.

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.

Three-Dimensional (3D) display device and method are disclosed. The device can include: a Light-Emitting Diode (LED) display, configured to display an image; a light path control structure including a multilayer pinhole type structure, configured to control emitting directions of light paths of the image to form 3D light field information, wherein multiple groups of pinhole arrays are arranged on each layer of the pinhole type structure; and a holographic function screen, configured to perform diffusion imaging on the 3D light field information to form a 3D image, wherein the LED display, the light path control structure and the holographic function screen are sequentially configured. The technical problems of the related art are solved.

A system and method making one or more holographic optical elements is disclosed. The method may include at least partially submerging a recording medium in an index matching fluid residing in a fluid reservoir. A first surface of the fluid reservoir may include a surface of a first optical coupling element. The method may include positioning the recording medium with respect to the surface of the first optical coupling element. The method may also include applying a first recording beam through the first optical coupling element, the index matching fluid, and a first portion of the recording medium to form a hologram in the first portion of the recording medium.

A method of correcting a holographic image, a processing device, a dark field digital holographic microscope, a metrology apparatus and an inspection apparatus. The method includes obtaining a holographic image; determining at least one attenuation function due to motion blur from the holographic image; and correcting the holographic image, or a portion thereof, using the at least one attenuation function.

Provided is a hologram transcription apparatus including: an exposure part; and a light source part for irradiating light to the exposure part. Here, the exposure part includes a transfer unit for transferring a hologram film, and the exposure part is rotatable to change an angle formed with the light.

A backlight unit for a holographic display is provided. The backlight unit includes: at least one light source; at least one input coupler; a light guide panel (LGP) that guides light; a first holographic element on a first surface of the LGP; and a second holographic element on a second surface of the LGP, wherein the at least one input coupler is configured to uniformly transmit rays emitted from the at least one light source toward the first holographic element through the LGP, and the LGP is configured to transmit the rays incident from the at least one input coupler toward the first holographic element, and the first holographic element redirects the rays toward the second holographic element, the redirected rays being substantially parallel to one another, and the second holographic element emits rays incident from the first holographic element toward an outside of the LGP.

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.

An ultra high-resolution near infrared brain imager system includes a modular cap housing closely spaced multiple vertical-cavity surface-emitting laser-single-photon avalanche photodiode array (VCSEL-SPAD) modules, each one of the VCSEL-SPAD modules including a linear VCSEL array and a SPAD detector.