Dispersion array and method of fabricating
View Patent ↗Optical spectrometers may be used to determine the spectral components of electromagnetic waves. Spectrometers may be large, bulky devices and may require waves to enter at a nearly direct angle of incidence in order to record a measurement. What is disclosed is an ultra-compact spectrometer with nanophotonic components as light dispersion technology. Nanophotonic components may contain metasurfaces and Bragg filters. Each metasurface may contain light scattering nanostructures that may be randomized to create a large input angle, and the Bragg filter may result in the light dispersion independent of the input angle. The spectrometer may be capable of handling about 200 nm bandwidth. The ultra-compact spectrometer may be able to read image data in the visible (400-600 nm) and to read spectral data in the near-infrared (700-900 nm) wavelength range. The surface area of the spectrometer may be about 1 mm 2 , allowing it to fit on mobile devices.
1 . A dispersion array, comprising:
a first dispersion structure configured to disperse light of a target wavelength range starting with a 0 degree dispersion of a target wavelength, wherein the first dispersion structure further comprises:
a first nanostructures layer having a first row of nanostructures and a second row of nanostructures, wherein the first row of nanostructures is parallel to the second row of nanostructures; and
a first filter layer;
wherein a distance between the first row of nanostructures and the second row of nanostructures is selected randomly from a probability distribution, and the first row of nanostructures is distributed from the second row of nanostructures according to the distance.
2 . The dispersion array of claim 1 , wherein the first nanostructures layer comprises nanoholes, nanorods, or nanoantennas.
3 . The dispersion array of claim 1 , wherein the first nanostructures layer comprises a dielectric or plasmonic material.
4 . The dispersion array of claim 1 , wherein the first dispersion structure is tuned to scatter and disperse light of the target wavelength range.
5 . The dispersion array of claim 1 , wherein the first row of nanostructures is parallel to a second row of nanostructures.
6 . The dispersion array of claim 5 , wherein the first row of nanostructures comprise nanoholes.
7 . The dispersion array of claim 6 , wherein the nanoholes are formed in a layer of TiO2.
8 . The dispersion array of claim 6 , wherein a radius of the nanoholes is half or less of a target wavelength of a wave in the target wavelength range of the first dispersion structure.
9 . The dispersion array of claim 6 , wherein spacing of the nanoholes within the first row of nanostructures allow lights within the target wavelength range to pass through the first row of nanostructures in one dimension without scattering.
10 . The dispersion array of claim 1 , wherein the distance between the first row of nanostructures and the second row of nanostructures is half a length of a wavelength selected from the target wavelength range of the first dispersion structure.
11 . The dispersion array of claim 1 , wherein the first filter layer comprises a distributed Bragg reflector, a dielectric mirror, a fiber Bragg grating, or a semiconductor Bragg mirror.
12 . The dispersion array of claim 1 , wherein the first filter layer comprises at least a first layer of a first thickness and a first material and a second layer of a second thickness and a second material that are alternately stacked on top of each other to form a stacked layer.
13 . The dispersion array of claim 12 , wherein the first layer comprises TiO2 and the second layer comprises SiO2.
14 . The dispersion array of claim 12 , wherein there are at least two sets of stacked layers.
15 . The dispersion array of claim 12 , wherein the first layer and the second layer that are alternatively stacked are able to disperse light of the target wavelength range of the first dispersion structure.
16 . The dispersion array of claim 12 , wherein the first dispersion structure comprises a defect layer.
17 . The dispersion array of claim 16 , wherein the first filter layer includes a defect layer.