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US 12,216,290 B2Granted
Color and multi-spectral image sensor based on 3D engineered material
AssigneeCalifornia Institute of Technology
InventorsPhilip Camayd-Munoz, Conner Ballew, Gregory Roberts, Andrei Faraon
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Abstract
Methods and devices to build and use multi-functional scattering structures. The disclosed methods and devices account for multiple target functions and can be implemented using fabrication methods based on two-photon polymerization or multi-layer lithography. Exemplary devices functioning as wave splitters are also described. Results confirming the performance and benefits of the disclosed teachings are also described.
Claims10
A method of splitting an electromagnetic wave into a plurality of waves with different wavelengths, the method comprising:
- applying the electromagnetic wave to a three-dimensional (3D) scattering structure at a first side thereof, the 3D scattering structure being formed into a set 3D pattern;
- scattering off the electromagnetic wave to generate a plurality of electromagnetic waves with different wavelengths, the plurality of electromagnetic waves exiting the 3D scattering structure at output second side thereof;
- and
- forming the 3D pattern using an optimization method employing a Gradient-based algorithm;
- wherein
- a target function of the Gradient-based algorithm is defined based on an electromagnetic intensity of the electromagnetic wave at target locations in a focal plane arranged outside the 3D structure;
- a sensitivity of the target function with respect to a refraction index at a point within the 3D structure is calculated based on a sigmoidal projection filter, the filter having a parameter to control a strength of the sigmoidal projection filter,
- wherein the sensitivity of the target function is calculated by:
- obtaining a uniform refraction index distribution based on an average of a maximum refraction index and a minimum refraction index;
- applying the sigmoidal filter to the uniform refraction index distribution, to obtain a filtered refraction index;
- adding the minimum refraction index to the filtered refraction index to obtain the refraction index at the point within the 3D structure, and
- increasing the strength of the sigmoidal projection filter from one iteration of the Gradient-based algorithm to another.
9 more elements
Dependencies are inferred from the claim text.