Tunable spectral filters

US11226503B2 · kind B2 · utility

Assignee

• The Government of the United States of America, as represented by the Secretary of the Navy · US

Inventors

• Marc Currie · Washington, US
• Virginia D. Wheeler · Alexandria, US
• Guy Beadie · Falls Church, US

Key dates

• Filing date: Dec 13, 2019
• Grant date: Jan 18, 2022
• Expiry date: Oct 5, 2040

Classification

• Technology area (CPC G): Physics
• CPC primary: G02F2203/055
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A tunable spectral filter comprising a phase change material is incorporated into a multilayered dielectric structure. The dielectric permittivity, and thus the filter properties, of the structure can be modified by producing a change in the phase change material, e.g., causing a metal-insulator transition. By controllably causing such a change in the dielectric permittivity of the phase change material, the spectral transmittance and reflectance of the structure, and thus its filter properties, can be modified to provide a predetermined transmittance or reflectance of electromagnetic radiation incident on the structure. In preferred embodiments, the phase change material layer is a vanadium dioxide (VO2) film formed by atomic layer deposition (ALD).