US 12,270,995 B2
Waveguide with four gradient coating
Yiren Xia, Milton Keynes (GB); and Timothy Smeeton, Milton Keynes (GB)
Assigned to ENVISICS LTD, Milton Keynes (GB)
Filed by Envisics Ltd, Milton Keynes (GB)
Filed on Aug. 31, 2023, as Appl. No. 18/240,594.
Application 18/240,594 is a continuation in part of application No. 18/141,311, filed on Apr. 28, 2023, granted, now 11,852,832.
Claims priority of application No. 2214069 (GB), filed on Sep. 27, 2022.
Prior Publication US 2024/0111153 A1, Apr. 4, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. G02B 27/01 (2006.01); F21V 8/00 (2006.01); G02B 27/00 (2006.01)
CPC G02B 27/0103 (2013.01) [G02B 6/0035 (2013.01); G02B 6/0055 (2013.01); G02B 27/0172 (2013.01); G02B 27/0081 (2013.01); G02B 2027/0109 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A waveguide comprising a pair of complementary surfaces arranged to provide waveguiding therebetween, wherein a first surface of the pair of complementary surfaces comprises a plurality of first layers, each first layer comprising a first dielectric, and a plurality of second layers, each second layer comprising a second dielectric, wherein each first and second layer has a first end and a second end, wherein a percentage change in the thickness of each layer from the first end to the second end of that layer has one of a plurality of discrete allowable values; wherein the total number of first and second layers is greater than the total number of discrete allowable values; and wherein a difference in refractive index between the first dielectric and second dielectric is greater than 0.4.