US 12,216,290 B2
Color and multi-spectral image sensor based on 3D engineered material
Philip Camayd-Munoz, Pasadena, CA (US); Conner Ballew, Pasadena, CA (US); Gregory Roberts, Pasadena, CA (US); and Andrei Faraon, Pasadena, CA (US)
Assigned to CALIFORNIA INSTITUTE OF TECHNOLOGY, Pasadena, CA (US)
Filed by CALIFORNIA INSTITUTE OF TECHNOLOGY, Pasadena, CA (US)
Filed on Jun. 29, 2022, as Appl. No. 17/853,540.
Application 17/853,540 is a division of application No. 16/656,156, filed on Oct. 17, 2019, granted, now 11,397,331.
Claims priority of provisional application 62/776,685, filed on Dec. 7, 2018.
Claims priority of provisional application 62/748,677, filed on Oct. 22, 2018.
Prior Publication US 2023/0122182 A1, Apr. 20, 2023
Int. Cl. G02B 27/10 (2006.01); G02B 5/02 (2006.01); H01L 27/146 (2006.01); H01P 1/207 (2006.01)
CPC G02B 27/1013 (2013.01) [G02B 5/0236 (2013.01); H01L 27/14625 (2013.01); H01L 27/14645 (2013.01); H01L 27/14685 (2013.01); H01P 1/207 (2013.01)] 10 Claims
OG exemplary drawing
 
1. 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.