Dynamic nanophotonic filter and method for tuning and fabricating the same

Patent metadata

Field	Value
Publication number	US-12529918-B2
Application number	US-202318304275-A
Country	US
Kind code	B2
Filing date	Apr 20, 2023
Priority date	Apr 20, 2022
Publication date	Jan 20, 2026
Grant date	Jan 20, 2026

Abstract

A dynamic nanophotonic filter and method for tuning and fabricating the same is disclosed. The filter includes a transparent substrate, a first layer of thermochromic VO 2 deposed on the substrate with a first thickness, a spacer layer having a spacer thickness and composed of a dielectric material deposed on the first layer, and a second layer of thermochromic VO 2 deposed on the spacer layer such that the spacer layer is sandwiched between the second and first layer. The dynamic nanophotonic filter changes between a semi-transparent state and an opaque state based on temperature. The semi-transparent state includes the first and second layers being insulating. The opaque state includes the first layer and the second layer both being metallic. The first thickness, the second thickness, and the spacer thickness are chosen to tune how the dynamic nanophotonic filter behaves in the semi-transparent state and the opaque states.

First claim

What is claimed is:

1 . A method for fabricating a tuned dynamic nanophotonic filter, comprising:
tuning a dynamic nanophotonic filter that changes between a semi-transparent state and an opaque state based on temperature, the dynamic nanophotonic filter comprising a transparent substrate, a first layer of thin-film thermochromic VO 2 , a spacer layer, and a second layer of thin-film thermochromic VO 2 , the tuning comprising choosing a first thickness of the first layer, a second thickness of the second layer, and a spacer thickness of the spacer layer such that the dynamic nanophotonic filter exhibits a desired behavior in at least one of the semi-transparent state and the opaque state; and fabricating the tuned dynamic nanophotonic filter by:
depositing a first precursor layer of vanadium directly onto a transparent substrate composed of calcium fluoride (CaF 2 );
oxidizing the first precursor layer until the vanadium of the first precursor layer is fully oxidized and the first precursor layer becomes the first layer of thin-film thermochromic VO 2 as determined by the examination of a first spectral transmittance, with the first precursor layer sized such that the first layer has the first thickness;
depositing the spacer layer directly onto the first layer, the spacer layer composed of intrinsic silicon and having the spacer thickness;
depositing a second precursor layer of vanadium directly onto the spacer layer; and
oxidizing the second precursor layer until the vanadium of the second precursor layer is fully oxidized and the second precursor layer becomes the second layer of thin-film thermochromic VO 2 as determined by the examination of a first spectral transmittance, with the second precursor layer sized such that the second layer has the second thickness.

2 . The method of claim 1 , wherein the spacer thickness is chosen to tune the dynamic nanophotonic filter to have a transmittance peak in a target spectral location when in the semi-transparent state.

3 . The method of claim 1 , wherein the first thickness and the second thickness are chosen to tune the dynamic nanophotonic filter to exhibit an attenuation when in the opaque state.

4 . The method of claim 1 , wherein the first thickness, the second thickness, and the spacer thickness are each chosen to tune the dynamic nanophotonic filter to maximize a power transmission difference between the semi-transparent state and the opaque state while the dynamic nanophotonic filter is exposed to a radiation.

5 . The method of claim 4 :
wherein the radiation is from a blackbody emitter at 900 K; wherein the first thickness and the second thickness are each 100 nm; and wherein the spacer thickness is 900 nm.

Assignees

• Chao Jeremy
• Wang Liping
• Taylor Sydney
• Univ Arizona State

Inventors

• Chao Jeremy
• Wang Liping
• Taylor Sydney

Classifications

• C23C14/083

  of refractory metals or yttrium · CPC title

• G02F2202/36

  Micro- or nanomaterials · CPC title

• C23C14/5853

  Oxidation · CPC title

• G02F2202/10

  semiconductor · CPC title

• C23C14/30

  by electron bombardment · CPC title