Methods and apparatus for transparent display using up-converting nanoparticles

Patent metadata

Field	Value
Publication number	US-9458989-B2
Application number	US-201314143558-A
Country	US
Kind code	B2
Filing date	Dec 30, 2013
Priority date	Jan 2, 2013
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

Disclosed herein are transparent color displays with nanoparticles made with nonlinear materials and/or designed to exhibit optical resonances. These nanoparticles are embedded in or hosted on a transparent substrate, such as a flexible piece of clear plastic or acrylic. Illuminating the nanoparticles with invisible light (e.g., infrared or ultraviolet light) causes them to emit visible light. For example, a rare-earth doped nanoparticle may emit visible light when illuminated simultaneoulsy with a first infrared beam at a first wavelength λ 1 and a second infrared beam at a second wavelength λ 2 . And a frequency-doubling nanoparticle may emit visible light when illuminated with a single infrared beam at the nanoparticle's resonant frequency. Selectively addressing these nanoparticles with appropiately selected pump beams yields visible light emitted from the nanoparticles hosted by the transparent substrate in a desired pattern.

First claim

What is claimed is:

1. A display comprising:
a transparent substrate;
at least one nanoparticle disposed on the transparent substrate, the at least one nanoparticle comprising a resonant structure configured to resonate at a visible wavelength λ v =(λ 1 λ 2 )/(λ 1 +λ 2 ) in response to illumination at a first wavelength λ 1 and a second wavelength λ 2 ;
a first light source, in optical communication with the at least one nanoparticle, to illuminate the at least one nanoparticle with a first infrared beam at the first wavelength λ 1 ; and
a second light source, in optical communication with the at least one nanoparticle, to illuminate the at least one nanoparticle with a second infrared beam at the second wavelength λ 2 while the first light source illuminates the at least one nanoparticle with the first infrared beam so as to cause the at least one nanoparticle to emit visible light,
wherein the visible light emitted by the at least one nanoparticle is at the visible wavelength λ v =(λ 1 λ 2 )/(λ 1 +λ 2 ).

2. The display of claim 1 , wherein the transparent substrate has a transmittance of about 90% to about 100% at wavelengths from about 390 nm to about 760 nm.

3. The display of claim 1 , wherein the transparent substrate comprises at least one of glass, plastic, polymer, and acrylic.

4. The display of claim 1 , wherein the at least one nanoparticle comprises a rare-earth element to emit the visible light in response to absorption, by the at least one nanoparticle, of at least a portion of the first infrared beam and at least a portion of the second infrared beam.

5. The display of claim 4 , wherein the rare-earth metal comprises at least one of erbium, thulium, europium, cerium, and terbium.

6. A display comprising:
a transparent substrate;
at least one nanoparticle disposed on the transparent substrate, the at least one nanoparticle comprising a resonant structure;
a first light source, in optical communication with the at least one nanoparticle, to illuminate the at least one nanoparticle with a first infrared beam at a first infrared wavelength λ 1 ; and
a second light source, in optical communication with the at least one nanoparticle, to illuminate the at least one nanoparticle with a second infrared beam at a second infrared wavelength λ 2 while the first light source illuminates the at least one nanoparticle with the first infrared beam so as to cause the at least one nanoparticle to emit visible light,
wherein the at least one nanoparticle comprises at least one of:
at least one first nanoparticle to emit light at a first visible wavelength between about 390 nm and about 490 nm;
at least one second nanoparticle to emit light at a second visible wavelength between about 490 nm and about 580 nm; and
at least one third nanoparticle to emit light at a third visible wavelength between about 580 nm and about 760 nm.

7. The display of claim 6 , further comprising:
at least one third light source, in optical communication with the transparent substrate, to illuminate the at least one second nanoparticle with a third infrared beam at a third infrared wavelength λ 3 ; and
at least one fourth light source, in optical communication with the transparent substrate, to illuminate the at least one third nanoparticle with a fourth infrared beam at a fourth infrared wavelength λ 4 .

8. The display of claim 1 , wherein the transparent substrate at least partially defines a cavity and the at least one nanoparticle comprises a plurality of nanoparticles, and further comprising:
a fluid, disposed within the cavity, in which the plurality of nanoparticles is suspended; and
a circulation system, in fluid communication with the fluid, to circulate the fluid so as to evenly distribute the plurality of nanoparticles within the cavity.

9. A display comprising:
a transparent substrate;
at least one nanoparticle disposed on the transparent substrate, the at least one nanoparticle comprising a resonant structure;
a first light source, in optical communication with the at least one nanoparticle, to illuminate the at least one nanoparticle with a first infrared beam at a first wavelength λ 1 ; and
a second light source, in optical communication with the at least one nanoparticle, to illuminate the at least one nanoparticle with a second infrared beam at a second wavelength λ 2 while the first light source illuminates the at least one nanoparticle with the first infrared beam so as to cause the at least one nanoparticle to emit visible light,
wherein the transparent substrate at least partially defines a cavity and the at least one nanoparticle comprises a plurality of nanoparticles, and further comprising:
a fluid, disposed within the cavity, in which the plurality of nanoparticles is suspended;
a circulation system, in fluid communication with the fluid, to circulate the fluid so as to evenly distribute the plurality of nanoparticles within the cavity, and
wherein the fluid comprises at least one of air and a liquid.

10. The display of claim 1 , wherein:
the first light source is configured to transmit the first infrared beam toward the at least one nanoparticle in a first direction substantially orthogonal to an optical axis of the transparent substrate, and
the second light source is configured to transmit the second infrared beam toward the at least one nanoparticle in a second direction substantially orthogonal to the optical axis of the transparent substrate.

11. The display of claim 10 , wherein the first direction is substantially orthogonal to the second direction.

12. The display of claim 1 , wherein the first wavelength is the same as the second wavelength.

13. The display of claim 1 , wherein the first wavelength is greater than the second wavelength.

14. The display of claim 1 , further comprising:
a reflective layer, disposed on one side of the transparent substrate, to reflect at least a portion of the visible light emitted by the at least one nanoparticle in a direction of a viewer.

15. A method of operating a display comprising at least one nanoparticle disposed on a transparent substrate, the method comprising:
(A) generating a first infrared beam at a first wavelength λ 1 ;
(B) generating a second infrared beam at a second wavelength λ 2 ;
(C) illuminating the at least one nanoparticle with the first infrared beam and the second infrared beam so as to cause the at least one nanoparticle to emit visible light at a visible wavelength λ v =(λ 1 λ 2 )/(λ 1 +λ 2 ) in a direction of a viewer, the at least one nanoparticle comprising a resonant structure configured to resonate at the visible wavelength λ v .

16. The method of claim 15 , wherein the first wavelength is the same as the second wavelength.

17. The method of claim 15 , wherein the first wavelength is greater than the second wavelength.

18. The method of claim 15 , wherein (C) comprises:
(i) transmitting the first infrared beam toward the at least one nanoparticle in a first direction substantially orthogonal to an optical axis of the transparent display; and
(ii) transmitting the second infrared beam toward the at least one nanoparticle in a second direction substantially orthogonal to the optical axis of the transparent display.

19. The method of claim 18 , wherein the first direction is substantially orthogonal to the second direction.

20. The method of claim 15 , wherein the at least one nanoparticle comprises a first nanoparticle disposed at a first location of the transparent substrate and a second nanoparticle d

Assignees

• Hsu Chia Wei
• Qiu Wenjun
• Zhen Bo
• Shapira Ofer
• Soljacic Marin
• Massachusetts Inst Technology

Inventors

• Hsu Chia Wei
• Qiu Wenjun
• Zhen Bo
• Shapira Ofer
• Soljacic Marin

Classifications

• F21V9/08

  for producing coloured light, e.g. monochromatic; for reducing intensity of light (with provision for controlling the colour F21V9/40) · CPC title

• G02B5/0242

  by means of dispersed particles · CPC title

• F21V9/12 Primary

  with liquid-filled chambers · CPC title

• Y10S977/773

  Nanoparticle, i.e. structure having three dimensions of 100 nm or less · CPC title

• B82Y20/00

  Nanooptics, e.g. quantum optics or photonic crystals · CPC title