Monolithic glass light shaping diffuser and method for its production

Abstract

A holographic light shaping diffuser (LSD) is formed from a monolithic glass material by recording light shaping structures (sometimes collectively known as “speckle”, particularly when the structures extend into the interior of the diffuser) in the glass material during its formation. A volume LSD may be produced by the photolithographic writing or other imaging of light shaping structures in a photosensitive glass material. Alternatively, a surface LSD may be produced by this imaging process or by embossing light shaping structures onto a high quality optical glass or by embossing a light shaping structures on a glass film layer coated onto a substrate. Both types of diffusers control the angular spread of transmitted light while homogenizing otherwise spatially noisy light sources such as LCDs and filamented light sources and while maintaining damage thresholds consistent with any glass optical element. The LSD has a transmission efficiency of over 90% from the Ultraviolet wavelengths through the physical spectrum and into the near-infrared. Moreover, because the LSD is a true glass, it is capable of withstanding temperatures well beyond glass transition temperatures of plastic LSDs, can be formed in a convex or concave surfaces through conventional molding, grinding, or polishing techniques, and can be coated by hot-coating techniques. The LSD also has a very high laser power threshold.