Main groups G03H 3/00 and G03H 5/00 are considered as marker for tagging the wave used, whatever the wave, detailed classes are given under subgroups of G03H 1/00.

Holography is a basic technology which developed in numerous application areas. A primary advantage of processing phase and amplitude information of an object wavefront is the ability of holography to reconstruct a 3D holobject from a recorded 3D object.

Whatever the application, G03H classification symbols are given for remaining pertinent holographic aspects.

Holography using optical waves i.e. electromagnetic radiations within the range of visible or near to visible (i.e. infrared, ultraviolet);

Applications wherein holography is an appropriate solution to a particular problem;

Systems for obtaining speckle reduction at recording or reconstruction; also applies to speckle reduction involved in numerical holography;

Systems for reducing the "space" x "spatial bandwidth" product; wherein the "space" measures the size of the hologram, the "spatial bandwidth" measures the "density" of holographic element, and the product reflects the total number of holographic elements forming the hologram; example : "horizontal parallax only" holograms comprise quasi-1D pertinent holographic information.

Holographic optical elements (HOEs, DOEs) are particular holograms wherein the holobject is a simple optical function (e.g. lens, mirror). Per se, HOEs are classified in G02B 5/32, however, their production is classified under G03H 1/04 (analogical record) or G03H 1/08 (digital record).

Recording material adapted to record holographic information:

organic material (e.g. Photopolymer, dichromated gelatine, Photoresists, Silver halide);

inorganic material (e.g. photorefractive crystal)

other recording means (e.g. CCD);

Details associated with the holographic record:

physical distribution storing in the hologram a print of the recorded interference pattern (variations of size, density, strength, charge, ...);

physical parameter affected when a reconstruction wave interacts with the hologram (amplitude, phase or polarisation variations);

nature of the holographic medium (e.g. thin, thick, volume holograms); dynamic of the variations (binary, discrete, continuous);

ageing and resistance of the material;

non-uniform thickness;

compound included into actinic material;

Mechanical aspect when related to holograms:

production line;

portable or mobile device;

moving component;

Involving specific optical component

phase mask; Diffuser;

optical filter;

amplitude, phase, or colour filter

particular location (e.g. in Fourier, holobject or image plane)

SLM as specific optical component

amplitude, signed amplitude , phase, polarisation, complex , amplitude/phase coupled or colour modulation;

EASLM, OASLM, XASLM, Acousto-optic modulator;

having movable pixels

1D, 2D, 3D modulation;

multiple SLMs (e.g. for multicolour processing):

having optical element in registration;

Object types:

diffusing, translucent and phase object;

2D (e.g. 2D SLM), 3D (e.g. 2D/3D) object;

holographic object

moving, coloured object;

numerical object (e.g. computer modelled or digitized real object);

decomposed object (e.g. 2D parallactic decomposition);

Laminate comprising hologram:

special arrangement of layers (e.g. printed layer);

functional layer (e.g. antireflective, colour tuning, enhancement, colour active, protective layer, polarisation, opaque or reflective layer);

Substrate aspect:

integrated surface relief hologram;

shape of the substrate (e.g. disc, ribbon, non-planar shapes)

kind of substrate (flexible, fibrous, metallic, plastic, crystalline or glass substrate);

Patterned hologram;

Light characteristics;

Particular processing of hologram record carrier, including

Copying holograms by holographic means including :

- Holograms synthesized from objects or objects from holograms.

In this sub-group, a digital representation of the hologram is mandatory.

- Hologram synthesis per se, comprising a numerical transform simulating light propagation (e.g. Fresnel or Fourier transforms) between object and hologram domains (for Computer Generated Hologram, CGH) or between holographic data and holobject (in digital holography).

- The main processing steps that may be involved are:

Processes or apparatus for obtaining a holobject from an analogical or numerical hologram;

Particular reconstruction arrangement including :

Dynamic of the holobject

Particular holobject including 2D, 3D, 2D+3D holobjects, rescaled or polarized holobjects;

Superposing or matching the holobject with other visual information;

Holobject having particular colour including achromatic, RGB, rainbow-like;

Particular location of the holobject with respect to the hologram, including in-plane, real, virtual or straddling holobject.

Details and isolated features involved during the reconstruction process are also classified under G03H 1/02.

Frame or time sequential multiplexing wherein a plurality of sub-holograms or holographic sub-frames are time multiplexed to reconstruct one holobject;

Double or multiple exposure recording process;

in-plane or depth multiplexing;

shape of the sub-hologram;

interleaved sub-holograms;

tiled identical holograms;

dot matrix holograms;

one steps and two steps holographic stereograms;

mechanically separated or in contact;

optically separated or in contact (optical contact in the sense that a reconstruction beam crosses the holograms);

made of different materials;

for spectral broadening (e.g. multicolour holobject);

comprising a HOE;

mixed volume/surface hologram;

superposed surface relief;

Details of the recording/reconstruction arrangement are also classified in respective classes in G03H 1/00.