Diffractive grating
AssigneeDispelix Oy
InventorsKasimir BLOMSTEDT, Jussi RAHOMÄKI, Ismo VARTIAINEN
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Abstract
The invention relates to a selective diffractive grating and applications thereof. The grating comprised in a periodic alternating pattern first material having a first dispersion curve (n1), and second material having a second dispersion curve (n2) different from the first dispersion curve (n1). According to the invention, the first and second dispersion curves (n−i, n 2) intersect each other at two or more different wavelengths (λ1 λ2).
Claims16
A two-dimensional waveguide comprising a diffractive grating arranged on a surface or within the waveguide, the diffractive grating comprising in a periodic alternating pattern
- first material having a first dispersion curve,
- second material having a second dispersion curve different from the first dispersion curve, wherein
- said first and second dispersion curves intersect each other at two or more different wavelengths.
The waveguide according to any of the preceding claims, wherein at least one of said materials is TiO2, HfO2 or ZrO2.
The waveguide according to any of the preceding claims, wherein the dispersion curves differ at least at some wavelength within the range of 380-750 nm by at least 0.05 units, in particular at least 0.1 units.
The waveguide according to any of the preceding claims, wherein the grating is arranged on a major surface of the waveguide.
The waveguide according to any of the preceding claims, comprising a stack of such gratings with different intersection wavelengths.
A diffractive waveguide stack comprising at least two superimposed waveguide layers, wherein at least one of the waveguide layers comprises a waveguide according to any of the preceding claims.
A method of manufacturing a two-dimensional waveguide comprising a selectively transparent diffractive grating, comprising
- selecting two or more different wavelengths,
- selecting a diffractive pattern configuration utilizing at least two different materials,
- selecting at least two different materials having different dispersion curves, which intersect each other at said two or more different wavelengths,
- manufacturing the grating on a surface or within the waveguide using said diffractive pattern configuration and said different materials therein.
Dependencies are inferred from the claim text.