Short-wavelength polarizing elements and the manufacture and use thereof
OwnerKoji Asakawa, Vincent Pelletier +4inventors
InventorsKoji Asakawa, Vincent Pelletier, Mingshaw Wu, Douglas Adamson, Richard Register, Paul Chaikin
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Abstract
While gold wire grids have been used to polarize infrared wavelengths for over a hundred years, they are not appropriate for shorter wavelengths due to their large period. With embodiments of the present invention, grids with periods a few tens of nanometers can be fabricated. Among other things, such grids can be used to polarize visible and even ultraviolet light. As a result, such wire grid polarizers have a wide variety of applications and uses, such as, e.g., in the fabrication of semiconductors, nanolithography, and more.
Claims27
A polarizing element, comprising:
- a substrate transparent to light;
- a polarization layer formed on said substrate;
- said polarization layer having polarization characteristics for said light;
- said polarization layer including an anisotropic striped structure parallel to said substrate;
- said striped structure having an average continuous distance of two or more times said light's wavelength in a longitudinal direction and having an average interval less than half of said light's wavelength in a transverse direction;
- wherein said polarization layer is formed by block copolymer lithography in which a pattern of block copolymer microdomains is transferred to said polarization layer;
- and
- wherein said striped structure is formed such that a plurality of the stripes have their longitudinal directions lying in parallel along a surface of the transparent substrate
A polarizing element with a substrate transparent to incident ultraviolet light and a polarization layer having polarization characteristics for said incident ultraviolet light, said polarizing element comprising:
- a polarization layer including two layers of striped structures, with said two layers of striped structures oriented substantially parallel to each other, and wherein the distance between the two layers is smaller than an incident ultraviolet light wavelength;
- and
- wherein said two layers of striped structures are oriented in the same direction, and the reflecting portions of said two layers are interdigitated.
A wire grid polarizer, comprising:
- a plurality of wires arranged substantially in parallel, wherein said wires are spaced at intervals of about 100 nm or less, and wherein said polarizer polarizes ultraviolet light.
A wire grid polarizer, comprising:
- a plurality of reflective wires arranged substantially in parallel, wherein said polarizer is effective at polarizing light in frequencies between a plasma frequency and 1/√2 of the plasma frequency with the grid rotated by about 90 degrees from its long-wavelength orientation to achieve the same polarization direction for a transmitted light.
A method of polarizing light with a wire grid polarizer, comprising:
- polarizing light with frequencies ω as high as ωp, wherein for 1<ωp/ω<√{square root over (1/r)} the grid is rotated by about 90 degrees from its long-wavelength orientation to achieve substantially the same polarization direction for the transmitted light.
A method of polarizing light with a wire grid polarizer, comprising:
- polarizing light with a polarizing element in which there is a crossover frequency at
- ω=ωp/√{square root over (2)}
- and below which frequency the grid cannot react fast enough to electric field changes, and E-polarization becomes transparent and H-polarization becomes reflective.
Dependencies are inferred from the claim text.