US 12,405,174 B2
Photonic markers enabling temperature sensing and/or security marking using low frame rate cameras
Ian Howard, Karlsruhe (DE); Dmitry Busko, Bruchsal (DE); Guojun Gao, Stutensee (DE); Ngei Katumo, Eggenstein-Leopoldshafen (DE); Andrey Turshatov, Griesheim (DE); and Bryce Richards, Stutensee-Blankenloch (DE)
Assigned to KARLSRUHER INSTITUTE FUR TECHNOLOGIE, (DE)
Appl. No. 17/788,383
Filed by Karlsruher Institut für Technologie, Karlsruhe (DE)
PCT Filed Dec. 23, 2020, PCT No. PCT/EP2020/087756
§ 371(c)(1), (2) Date Jun. 23, 2022,
PCT Pub. No. WO2021/130304, PCT Pub. Date Jul. 1, 2021.
Claims priority of application No. 19219261 (EP), filed on Dec. 23, 2019.
Prior Publication US 2023/0022560 A1, Jan. 26, 2023
Int. Cl. G01N 21/63 (2006.01); G01K 11/32 (2021.01)
CPC G01K 11/32 (2013.01) [G01N 21/63 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A photonic marker system comprising:
at least one photonic marker comprising a host material selected from the group consisting of a rare earth element oxysulfide and strontium aluminate, wherein the host material is doped with Eu3+ or Eu2+ as a dopant;
a pulsed light source having an excitation wavelength in the range of from 300 to 700 nm for exciting the at least one photonic marker so that the at least one photonic marker emits photoluminescence, the intensity of which decays over time;
a video camera having a frame rate of equal to or more than 20 frames per second (fps) and equal to or less than 2000 fps for detecting a photoluminescence intensity of the at least one photonic marker in a time-resolved manner to determine a time-resolved photoluminescence intensity of the at least one photonic marker; and
a processor configured to determine a temperature of a sample to which the at least one photonic marker is added by comparing the time-resolved photoluminescence intensity of the at least one photonic marker with a predetermined temperature-dependent photoluminescence profile of the at least one photonic marker,
wherein both the light source and the video camera are part of a portable electronic device selected from the group consisting of a smartphone and a tablet computer.