US 11,789,284 B2
Optical layered composite having a coating thickness below a threshold and its application in augmented reality
Jens Ulrich Thomas, Mainz (DE); Thorsten Damm, Eltville am Rhein (DE); Frank-Thomas Lentes, Bingen (DE); and Kurt Nattermann, Ockenheim (DE)
Assigned to Schott AG, Heidenheim (DE)
Filed by Schott AG, Mainz (DE)
Filed on Aug. 1, 2019, as Appl. No. 16/529,271.
Claims priority of application No. 18186912 (EP), filed on Aug. 1, 2018.
Prior Publication US 2020/0041804 A1, Feb. 6, 2020
Int. Cl. G02B 27/14 (2006.01); G02B 27/01 (2006.01); G02B 27/09 (2006.01); G02B 27/10 (2006.01)
CPC G02B 27/142 (2013.01) [G02B 27/0172 (2013.01); G02B 27/095 (2013.01); G02B 27/1073 (2013.01); G02B 2027/0178 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An optical layered composite, comprising:
a substrate having a front face, a back face, a thickness ds between the front face and the back face and a refractive index ns; and
a coating applied to the front face, the coating comprising one or more coating layers, wherein, for at least one wavelength λg in the range from 390 nm to 700 nm, the coating satisfies one of the following criterion:

OG Complex Work Unit Math
wherein nc is a mean refractive index of the coating layers, weighted by thickness, wherein dc is a total thickness of the coating, wherein thicknesses are determined in a direction perpendicular to the front face, and wherein k=λg/4π, wherein a total thickness variation is less than 2 μm, wherein the optical layered composite is configured to transversely propagate light introduced into the optical layered composite.