Optical detector

Patent metadata

Field	Value
Publication number	US-11573125-B2
Application number	US-202016999461-A
Country	US
Kind code	B2
Filing date	Aug 21, 2020
Priority date	Aug 23, 2019
Publication date	Feb 7, 2023
Grant date	Feb 7, 2023

Abstract

Embodiments of the present disclosure generally relate to apparatus for and methods of detecting light utilizing the spin Seebeck effect (SSE). In an embodiment, a method for detecting broadband light is provided. The method includes generating a SSE in a device by illuminating the device with light, the device comprising a bilayer structure disposed over a substrate, the bilayer structure comprising a non-magnetic metal layer and a magnetic insulator layer. The method further includes measuring the SSE based on a field modulation method, determining, based on the measuring, an optically-created thermal gradient of the device, and detecting a wavelength range of the light. Apparatus for detecting broadband light are also described.

First claim

What is claimed is:

1. A method for detecting broadband light, comprising:
generating a spin Seebeck effect (SSE) in a device by illuminating the device with light, the device comprising a bilayer structure disposed over a substrate, the bilayer structure comprising a non-magnetic metal layer and a magnetic insulator layer;
measuring the SSE based on a field modulation method;
determining, based on the measuring, an optically-created thermal gradient of the device; and
detecting a wavelength range of the light.

2. The method of claim 1 , wherein a magnetic field is applied to the device in a direction perpendicular to a light direction.

3. The method of claim 1 , wherein a magnetic field is applied to the device in a direction parallel to a light direction.

4. The method of claim 1 , wherein detecting a wavelength range comprises:
generating a voltage in the device using the SSE; and
detecting the generated voltage.

5. The method of claim 1 , wherein the wavelength range is from about 390 nm to about 2200 nm.

6. The method of claim 1 , wherein the non-magnetic metal layer comprises Pt, W, Ir, Ru, Pd, Cu, Au, Bi, Ta, or a non-magnetic alloy thereof.

7. The method of claim 1 , wherein the magnetic insulator layer comprises nickel ferrite, a rare earth iron garnet, or a combination thereof.

8. The method of claim 7 , wherein the rare earth iron garnet comprises yttrium iron garnet, europium iron garnet, thulium iron garnet, lutetium iron garnet, gadolinium iron garnet, or a combination thereof.

9. The method of claim 1 , wherein the substrate comprises gadolinium gallium garnet, yttrium aluminum garnet, strontium titanium oxide, neodymium gallium garnet, silicon, or a combination thereof.

10. The method of claim 1 , wherein the non-magnetic metal layer has a thickness of less than about 6 nm.

11. An apparatus for detecting broadband light, comprising:
a multilayer structure, the multilayer structure configured to generate an electrical voltage from a spin current;
an electromagnet configured to apply a magnetic field to the multilayer structure;
a voltmeter coupled to the multilayer structure;
an excitation source to emit light, the excitation source optically coupled to the multilayer structure; and
an optical device configured to direct the light towards the multilayer structure, the optical device comprising:
a plurality of reflecting facets;
a linear polarizer;
a wave plate; and
an optical chopper.

12. The apparatus of claim 11 , wherein the multilayer structure comprises:
a substrate;
a magnetic insulator layer disposed over the substrate; and
a non-magnetic metal layer disposed over a magnetic insulator layer.

13. The apparatus of claim 12 , wherein:
the non-magnetic metal layer comprises Pt, W, Ir, Ru, Pd, Cu, Au, Bi, Ta, or a non-magnetic alloy thereof;
the magnetic insulator layer comprises nickel ferrite, a rare earth iron garnet, or a combination thereof;
the substrate comprises gadolinium gallium garnet, yttrium aluminum garnet, strontium titanium oxide, neodymium gallium garnet, silicon, or a combination thereof; or
a combination thereof.

14. The apparatus of claim 13 , wherein the rare earth iron garnet comprises yttrium iron garnet, europium iron garnet, thulium iron garnet, lutetium iron garnet, gadolinium iron garnet, or a combination thereof.

15. The apparatus of claim 12 , wherein:
the non-magnetic metal layer comprises Pt;
the magnetic insulator layer comprises yttrium iron garnet; and
the substrate comprises gadolinium gallium garnet.

16. The apparatus of claim 11 , wherein the electromagnet is further configured to rotate about an axis of the multilayer structure.

17. An apparatus for detecting broadband light, comprising:
a thermal electric cooler;
a heat sink disposed over at least a portion of the thermal electric cooler, the heat sink thermally coupled to the thermal electric cooler;
a multilayer structure disposed over at least a portion of the heat sink, the multilayer structure comprising a substrate, a magnetic insulator layer disposed over the substrate, and a non-magnetic metal layer disposed over the magnetic insulator layer; and
a voltmeter coupled to the multilayer structure.

18. The apparatus of claim 17 , wherein:
the non-magnetic metal layer comprises Pt, W, Ir, Ru, Pd, Cu, Au, Bi, Ta, or a non-magnetic alloy thereof;
the magnetic insulator layer comprises nickel ferrite, a rare earth iron garnet, or a combination thereof;
the substrate comprises gadolinium gallium garnet, yttrium aluminum garnet, strontium titanium oxide, neodymium gallium garnet, silicon, or a combination thereof; or
a combination thereof.

19. The apparatus of claim 17 , wherein:
the non-magnetic metal layer comprises Pt;
the magnetic insulator layer comprises yttrium iron garnet; and
the substrate comprises gadolinium gallium garnet.

20. The apparatus of claim 17 , wherein the non-magnetic metal layer has a thickness of less than about 6 nm.

Assignees

• Univ Wyoming

Inventors

• Rice William D
• Kattel Subash
• Murphy Joseph R

Classifications

• G01J5/10

  using electric radiation detectors · CPC title

• G01J3/457 Primary

  Correlation spectrometry, e.g. of the intensity (G01J3/453 takes precedence) · CPC title

• G01J1/0429

  using polarisation elements · CPC title

• G01J5/485

  Temperature profile · CPC title

• G01J2001/4295

  using a physical effect not covered by other subgroups of G01J1/42 · CPC title