An optical article including a substrate, and a holographic waveguide covering at least part of the substrate and including two main surfaces, at least one of them conforming to a surface of the substrate, and at least first and second zones that are configured so that light incoming on one of the first and second zones is at least partially guided towards the other of the first and second zones.

An optical system comprises an imaging holographic optical element, which produces a floating hologram. An upstream light-forming holographic optical element causes spectral filtering of the light.

A method of enlarging an observation window from which the reconstruction from a Computer Generated Hologram (CGH) may be viewed, including reproducing a CGH, and shifting a location of an exit pupil or observation window of an optical system reproducing the CGH. A method of increasing a viewing angle from which the reconstruction from a Computer Generated Hologram (CGH) may be seen, including producing a plurality of instances of a CGH, projecting each one of the instances in a different direction so that a first exit pupil of a first instance is close to a second exit pupil of a second instance. An optical system including a plurality of exit pupils associated with a plurality of optical components, further including a light deflector for jittering a location of a first exit pupil so as to increase an overlap of the first exit pupil with a second exit pupil. Related apparatus and methods are also described.

A method for despeckling the image reproduced by a Computer Generated Hologram (CGH) including reproducing a CGH, and jittering a location of an exit pupil of an optical system through which the CGH is imaged, relative to an observer's input pupil, so as to shift at least some speckles out of the exit pupil. A method for despeckling a Computer Generated Holographic image including computing a first modulation for a first holographic image, and computing a second modulation for a second holographic image of a same holographic image using an initial phase distribution used for calculating the first holographic image as an initial phase distribution used for calculating the second modulation. Related apparatus and methods are also described.

Provided is a recording method with which wasteful consumption of the M number (M/#) of the recording material is prevented, and with which the recording density is improved. An optical information recording device that utilizes interference between signal light and reference light to record information on an optical information recording medium is equipped with: a light source that emits light toward an optical recording medium; a beam-splitting element that splits the emission light emitted from the light source into signal light and reference light; and a reference light angle control unit that controls the incidence angle of the reference light with respect to the optical information recording medium. The optical recording medium is irradiated with the signal light as a spherical wave and is irradiated with the reference light as a planar wave, and when information is recorded on the optical information recording medium, the optical information recording medium is irradiated such that there exists in the interior of the optical information recording medium a region which is exposed only to the signal light, a region which is exposed only to the reference light, and a region which is exposed to overlapping signal light and reference light.