Methods of fabricating infrared bandpass filters and infrared bandpass filters fabricated thereby

A method for fabrication of an infrared (IR) bandpass filter, the method comprising:

• providing a mold comprising an array of nanoscale-sized recesses or protuberances;
• depositing a sacrificial material on the array of nanoscale-sized recesses or protuberances of the mold to form a sacrificial layer thereon;
• depositing a metallic material comprising gold (Au) on the sacrificial layer such that the metallic material is received within the recesses or between the protuberances of the mold to form a metallic layer thereon;
• depositing a dielectric material on the metallic layer that is received within the recesses or between the protuberances of the mold to form a dielectric spacer layer thereon;
• depositing a stress-absorbing material on the dielectric spacer layer to form a stress-absorbing layer thereon;
• performing an etching process to selectively remove the sacrificial layer;
• applying an adhesive, water-soluble film to the stress-absorbing layer;
• applying a force to the stress-absorbing layer by pulling on the water-soluble film to peel a first intermediate structure from the mold, wherein the first intermediate structure comprises the water-soluble film, the metallic layer, the dielectric spacer layer, and the stress-absorbing layer;
• selectively removing the water-soluble film from the first intermediate structure by dissolving the water-soluble film with water to define a second intermediate structure comprising the metallic layer, the dielectric spacer layer, and the stress-absorbing layer;
• selectively removing the stress-absorbing layer from the second intermediate structure by dissolving the stress-absorbing layer with acetone to define a third intermediate structure comprising the metallic layer and the dielectric spacer layer;
• and
• transferring the third intermediate structure to a receiver substrate to define the infrared (IR) bandpass filter;
• wherein the metallic and dielectric spacer layers comprise nanoholes or nanoposts formed by the array of nanoscale-sized recesses or protuberances of the mold;
• wherein the nanoholes or nanoposts of the metallic and dielectric spacer layers are configured to function as quasi three dimensional (quasi 3D) plasmonic metal dielectric hybrid nanostructures.

A method of fabricating an infrared (IR) bandpass filter, the method comprising:

• forming metallic and dielectric spacer layers on a mold, the metallic and dielectric spacer layers comprising nanoscale-sized recesses or protuberances defined by the mold;
• depositing a stress-absorbing layer on the dielectric spacer layer opposite the mold, wherein the stress-absorbing layer comprises an acrylic;
• applying a force to the stress-absorbing layer to peel a first intermediate structure comprising the metallic layer, the dielectric spacer layer, and the stress-absorbing layer from the mold;
• selectively removing the stress-absorbing layer from the first intermediate structure with a first solvent configured to dissolve the stress-absorbing layer to define a second intermediate structure comprising the metallic layer and the dielectric spacer layer;
• and
• transferring the second intermediate structure to a receiver substrate to define the infrared (IR) bandpass filter, wherein the recesses or protuberances of the metallic and dielectric spacer layers are configured to function as quasi three dimensional (quasi 3D) plasmonic metal dielectric hybrid nanostructures.