Spectrum filtering for visual displays and imaging having minimal angle dependence
AssigneeThe Regents of the University of Michigan
InventorsLingjie Jay Guo, Ting Xu
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Abstract
An optical spectrum filtering device, e.g., color filter, having reduced angle dependence is provided that comprises an interference filter assembly comprising a high refractive index dielectric material, such as a Fabry-Perot based resonator structure. The filter assembly is capable of transmitting a portion of an electromagnetic spectrum into the dielectric material to generate a filtered output with a predetermined range of wavelengths that displays minimal angle dependence, when viewed from a range of incidence angles ranging from normal (0°) to 90°. Methods of making minimal angle dependent optical spectrum filters and reducing angle dependence for such devices are also provided.
Claims24
An optical spectrum filtering device comprising:
- an interference filter assembly comprising a dielectric material having a refractive index of greater than about 1.5 disposed between a pair of parallel reflective surfaces;
- wherein the filter assembly is capable of transmitting a portion of an electromagnetic spectrum to generate a filtered output having a predetermined range of wavelengths that displays minimal angle dependence.
An optical spectrum filtering device comprising:
- an interference filter assembly comprising a dielectric material having a refractive index of greater than about 1.5 disposed between a pair of parallel reflective surfaces, wherein each reflective surface comprises a metal;
- and
- wherein the filter assembly is capable of transmitting a portion of an electromagnetic spectrum into the dielectric material to generate a filtered output having a predetermined range of wavelengths that exits the filter assembly, wherein the filtered output has a predetermined range of wavelengths and displays minimal angle dependence so that the predetermined range of wavelengths varies less than or equal to about 50 nm from an incidence angle of 0 to an incidence angle of 90°.
An optical spectrum filtering device comprising:
- an interference filter assembly comprising a high refractive index dielectric material disposed between a pair of parallel reflective surfaces, wherein each reflective surface comprises a distributed Bragg Reflector (DBR) or a 1-dimensional photonic crystal;
- and
- wherein the filter assembly is capable of transmitting a portion of an electromagnetic spectrum into the dielectric material to generate a filtered output having a predetermined range of wavelengths that exits the filter assembly, wherein the filtered output has a predetermined range of wavelengths and displays minimal angle dependence.
A method of making an optical spectrum filtering device having minimal angle dependence, the method comprising:
- applying a polymeric resist material to a dielectric material having a refractive index of greater than about 2 and contacting the polymeric resist with a mold having a predetermined height;
- etching the polymeric resist and dielectric material;
- and
- applying a metal over the remaining dielectric material to form an interference filter assembly having the refractive index of greater than about 2 comprising a pair of parallel reflective surfaces, wherein a filtered output from the interference filter assembly generates a predetermined range of wavelengths that displays minimal angle dependence.
A method of reducing angle dependence of an optical spectrum filtering device, the method comprising:
- incorporating a dielectric material having a refractive index of greater than about 1.5 into an interference filter assembly comprising a pair of parallel reflective surfaces, wherein each reflective surface comprises a metal;
- so that the filter assembly generates a filtered output having a predetermined range of wavelengths that deviates less than or equal to 50 nm when the filter assembly is observed from incidence angles ranging from 0 to 90°.
An optical spectrum filtering device comprising:
- a resonance filter assembly that displays minimal angle dependence comprising a resonator structure comprising an electrically conductive metal grating structure that forms an optical metamaterial, wherein the electrically conductive metal grating structure comprises at least two openings capable of transmitting a portion of an electromagnetic spectrum to generate a filtered and polarized output having a predetermined range of wavelengths via optical resonance.
Dependencies are inferred from the claim text.