Low-cost thin-metal-film interference filters
First Claim
Patent Images
1. A filter for filtering electromagnetic radiation, comprising:
- a dielectric layer having a first side and an opposite second side and having a selected thickness measured from said first side to said second side; and
first and second metal films respectively disposed on said first and second sides of said dielectric layer to form an optical cavity enclosing said dielectric layer, said first and second metal films having a thickness less than a penetration depth of the radiation,wherein said optical cavity is operable to transmit radiation at a selected wavelength with a predetermined bandwidth, and said dielectric layer, said first and second metal films are configured to have a total optical thickness greater than one half of said selected wavelength and less than said selected wavelength.
4 Assignments
0 Petitions
Accused Products
Abstract
Interference filters and filter arrays based on thin-metal film interference filters having at least one dielectric layer formed between two thin-metal films to form a Fabry-Perot cavity.
388 Citations
13 Claims
-
1. A filter for filtering electromagnetic radiation, comprising:
-
a dielectric layer having a first side and an opposite second side and having a selected thickness measured from said first side to said second side; and first and second metal films respectively disposed on said first and second sides of said dielectric layer to form an optical cavity enclosing said dielectric layer, said first and second metal films having a thickness less than a penetration depth of the radiation, wherein said optical cavity is operable to transmit radiation at a selected wavelength with a predetermined bandwidth, and said dielectric layer, said first and second metal films are configured to have a total optical thickness greater than one half of said selected wavelength and less than said selected wavelength. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. An optical filter for transmitting a selected spectral component in an input optical beam, comprising:
-
a first metal layer configured to have a thickness less than a penetration depth for said input optical beam; a first dielectric layer formed on said first metal layer; a second metal layer formed on said first dielectric layer and configured to have a thickness less than a penetration depth for said input light beam; a second dielectric layer formed on said second metal layer; and a third metal layer formed on said second dielectric layer and configured to have a thickness less than a penetration depth for said input light beam, wherein said first and second dielectric layers are configured to allow for transmission of said selected spectral component. - View Dependent Claims (8, 9, 10)
-
-
11. An optical filter for filtering a white input beam to produce a colored transmitted beam, comprising an array of filter elements disposed relative to one another and formed on a substrate, each filter element comprising three adjacent color filters formed of a stack of alternating metal layers and dielectric layers on said substrate for transmitting different colors, wherein each color filter includes:
-
a first metal layer formed on said substrate and configured to have a thickness less than a penetration depth for said input beam; a first dielectric layer formed on said first metal layer; a second metal layer formed on said first dielectric layer and configured to have a thickness less than a penetration depth for said input beam; a second dielectric layer formed on said second metal layer; and a third metal layer formed on said second dielectric layer and configured to have a thickness less than a penetration depth for said input beam, wherein said first and second dielectric layers are configured to allow for transmission of a selected spectral component in said input beam. - View Dependent Claims (12, 13)
-
Specification