Optical converter for high luminances

Patent metadata

Field	Value
Publication number	US-9738828-B2
Application number	US-201414262064-A
Country	US
Kind code	B2
Filing date	Apr 25, 2014
Priority date	Oct 25, 2011
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

An optical converter for producing colored or white light from blue excitation light is provided. The converter has good scattering properties to be able to produce nearly white light from the scattered blue light components and the scattered, converted yellow light components. The optical converter includes material including one or more of a YAG ceramic, a LuAG ceramic, and a magnesium-aluminum ceramic exhibiting strong scattering.

First claim

The invention claimed is:

1. A converter for producing colored or white light from blue excitation light, comprising:
a converter body having an excitation face and an opposite face, the spacing therebetween defining the thickness of the converter body, the converter body comprising a cerium doped optoceramic converter material selected from the group consisting of a YAG ceramic, a LuAG ceramic, and a magnesium-aluminum ceramic, wherein the optoceramic converter material has a degree of cerium doping and is sintered at a temperature that are sufficient to provide an embedded grain structure in the doped optoceramic material which exhibits scattering to obtain an emission spot of a common size as a cross section of a light beam of the excitation light, to obtain a remission factor of longer wavelength light of 600 nm wavelength of R emission >0.6, and to obtain a quantum efficiency QE of greater than 0.80.

2. The converter as claimed in claim 1 , wherein the thickness of the converter body is used for fine-tuning fractions of remitted excitation light and remitted longer wavelength light.

3. The converter as claimed in claim 1 , wherein the optoceramic converter material is a doped YAG ceramic comprising cerium doped Y 3 Al 5 O 12 .

4. The converter as claimed in claim 1 , wherein the optoceramic converter material is a LuAG ceramic comprising cerium doped Lu 3 (Ga,Al) 5 O 12 .

5. The converter as claimed in claim 1 , wherein the optoceramic converter material is a magnesium-aluminum ceramic comprising cerium doped Mg 3 Al 8 [SiO] 3 .

6. The converter as claimed in claim 1 , wherein the optoceramic converter material is doped with an amount of Ce 2 O 3 in a range from 0.01 to 2%.

7. The converter as claimed in claim 1 , wherein the optoceramic converter material is doped with an amount of Ce 2 O 3 in a range from 0.3 to 1%.

8. The converter as claimed in claim 1 , wherein the optoceramic converter material is doped with an amount of Ce 2 O 3 in a range from 0.1 to 0.5%.

9. The converter as claimed in claim 1 , wherein the thickness of the converter body is 1 mm thickness.

10. The converter as claimed in claim 1 , further comprising an optical figure of merit of QE*R emission >0.6.

11. The converter as claimed in claim 1 , wherein the optoceramic converter material has a thermal figure of merit (FOM therm,stat )>1000 (W/m), and wherein said thermal figure of merit is calculated as FOM therm =thermal conductivity*min(T fail ,T 0.8 quench ).

12. The converter as claimed in claim 1 , wherein the optoceramic converter material has a thermal conductivity of at least 5 W/m*K.

13. The converter as claimed in claim 1 , wherein the optoceramic converter material has a thermal conductivity of at least 10 W/m*K.

14. The converter as claimed in claim 1 , wherein the optoceramic converter material has a thermal conductivity of at least 12 W/m*K.

15. The converter as claimed in claim 1 , further comprising a luminance of >>100 cd/mm 2 in a static operation mode.

16. The converter as claimed in claim 1 , further comprising a mirror secured to the opposite face.

17. The converter as claimed in claim 1 , wherein the excitation face is coated with a dichroic filter.

18. The converter as claimed in claim 1 , comprising scattering properties that remit between 10% and 30% of the excitation light that, in combination with the excitation light, converted light leads to a white color impression for the viewer.

19. The converter as claimed in claim 1 , further comprising a scattering layer at the excitation face to provide scattering properties that remit between 10% and 30% of the excitation light that achieves a white light-near region.

20. The converter as claimed in claim 1 , wherein the excitation face is roughened to provide scattering properties that remit between 10% and 30% of the excitation light that achieves a white light-near region.

21. A converter for producing colored or white light from blue excitation light, comprising:
a converter body having an excitation face and an opposite face, the spacing therebetween defining the thickness of the converter body, wherein the converter material comprises a cerium doped optoceramic having a degree of cerium doping and being sintered at a temperature that are sufficient to provide an embedded grain structure in the doped optoceramic which exhibits scattering to obtain an emission spot of a common size as the cross section of the light beam of the excitation light, to obtain a remission factor of longer wavelength light of 600 nm wavelength of R emission >0.6, and to obtain a quantum efficiency QE of greater than 0.80, wherein the converter material is a doped YAG ceramic or LuAG ceramic.

22. A converter comprising a ceramic converter material having a cerium doped optoceramic that has a degree of cerium doping and is sintered at a temperature that are sufficient to provide an embedded grain structure in the doped optoceramic so that the ceramic converter material exhibits an optical figure of merit of FOM opt =QE*R emission that is greater than 0.5, wherein the QE is a quantum efficiency and the R emission is a remission factor of longer wavelength light of 600 nm wavelength.

23. The converter as claimed in claim 22 , wherein the optical figure of merit of FOM opt =QE*R emission that is greater than 0.7.

24. The converter as claimed in claim 22 , wherein the optical figure of merit of FOM opt =QE*R emission that is greater than 0.8.

Assignees

• Schott Ag

Inventors

• Hagemann Volker
• Nass Peter
• Menke Yvonne
• Hoppe Bernd
• Beier Wolfram
• Liebald Rainer
• Schultz Niko
• Weidmann Guenter
• Esemann Hauke

Classifications

• F21V9/45

  by adjustment of photoluminescent elements · CPC title

• F21V13/08

  the elements being filters or photoluminescent elements and reflectors · CPC title

• C04B2235/3286

  Gallium oxides, gallates, indium oxides, indates, thallium oxides, thallates or oxide forming salts thereof, e.g. zinc gallate · CPC title

• C04B2235/763

  Spinel structure AB2O4 · CPC title

• C09K11/646

  Silicates · CPC title