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US 12,481,245 B2Granted
Method and apparatus for filtering noise for holographic display
AssigneeSeoul National University R&Db Foundation
InventorsKiseung Bang, Changwon Jang, Byoungho Lee
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Abstract
A method and apparatus for filtering noise for a holographic display are provided. The noise filtering apparatus includes a first filter implemented using a volume grating for filtering DC noise in light modulated by a spatial light modulator or a second filter implemented using a volume grating or a thin-film filter, which filters high-order noise in the light.
Claims4
A noise filtering apparatus for a holographic display, the noise filtering apparatus comprising:
- a first filter implemented using a volume grating for filtering DC noise in light modulated by a spatial light modulator;
- and
- a second filter implemented using a volume grating or a thin-film filter, which filters high-order noise in the light passing through the first filter,
- the first filter comprises:
- a first photo-thermo-refractive (PTR) transparent substrate;
- and
- a first volume grating engraved in the first PTR transparent substrate,
- wherein grating pattern intervals of the first volume grating are arranged to form a ring-shaped stop band of 0.5° or less when a Bragg angle is a first angle other than 0°,
- the first filter is arranged at an inclination of the first angle with respect to the spatial light modulator, and
- the DC noise output from the spatial light modulator at 0° is incident on the first filter at the first angle and is removed through the stop band of the first filter.
7 more elements
A noise filtering method for a holographic display, the method comprising:
- filtering DC noise in light modulated by a spatial light modulator, by using a first filter implemented using a volume grating;
- and
- filtering high-order noise in the light passing through the first filter by using a second filter implemented using a volume grating or a thin-film filter,
- the first filter comprises:
- a first photo-thermo-refractive (PTR) transparent substrate;
- and
- a first volume grating engraved in the first PTR transparent substrate,
- wherein grating pattern intervals of the first volume grating are arranged to form a ring-shaped stop band of 0.5° or less when a Bragg angle is a first angle other than 0°,
- the first filter is arranged at an inclination of the first angle with respect to the spatial light modulator, and
- the DC noise output from the spatial light modulator at 0° is incident on the first filter at the first angle and is removed through the stop band of the first filter.
7 more elements
Dependencies are inferred from the claim text.