Method and device for the layered production of thin volume grid stacks, and beam combiner for a holographic display

Abstract

The invention relates to a method and to a device for the layered production of at least one volume grid (VG) in a recording medium (AZM) by exposure to light, which comprises at least one light sensitive layer which is sensitized for a predeterminable wavelength (?) of the exposure light. Each volume grid (VG) is generated in the recording medium (AZM) by at least two interference capable wave fronts (WF1, WF2) of coherent light, which are superimposed at a predeterminable depth (z) at a predeterminable angle (2?) in the recording medium (AZM) with a predeterminable interference contrast V(z).; The depth (z) and the thickness of the refractive index and / or transparency modulation of a volume grid (VG) in the recording medium (AZM) are adjusted in the direction of light propagation (z) by a depth dependent control of the spatial and / or temporal coherence degree (?) of the interfering wave fronts (WF1, WF2). The invention further relates to a beam combiner for a holographic display and to a solar module having increased efficiency.

Description

technical field [0001] The present invention relates to methods and devices for layered generation of thin body grating stacks. The invention also relates to beam combiners for holographic displays. Background technique [0002] Diffractive optical elements (DOEs) play a special role in the fabrication of holographic visual displays. These elements, typically provided in the form of transparent films with a pre-determinable thickness, affect the light beams, which project the light beams from the image-generating device, such as large-area light modulators (SLMs), by diffractive effects rather than by refraction. In this way, the total thickness of beam affecting elements placed downstream of the SLM in the path when viewed in the direction of light propagation and preferably comprising light-refractive elements such as lenses, prisms, etc., can be kept very low compared to projection displays. [0003] However, the influence of light emitted by the pixels of the SLM neces...

AI Technical Summary

Problems solved by technology

One problem, however, is the generation of volume gratings in large-area recording media, since the surface area of ​​the recording medium is determined by the exit faces of the prisms

However, this absorption method does not allow multiple thin volume grating layers to be given separate longitudinal apodization distributions in thicker recording media

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