US 12,253,414 B2
Image sensor and preparation method thereof, and electronic device
Youming Zhang, Shenzhen (CN); and Lifeng Sun, Shenzhen (CN)
Assigned to Huawei Technologies Co., Ltd., Shenzhen (CN)
Filed by HUAWEI TECHNOLOGIES CO., LTD., Guangdong (CN)
Filed on Jun. 30, 2022, as Appl. No. 17/855,313.
Application 17/855,313 is a continuation of application No. PCT/CN2019/130438, filed on Dec. 31, 2019.
Prior Publication US 2022/0341782 A1, Oct. 27, 2022
Int. Cl. G01J 3/28 (2006.01); H01L 27/146 (2006.01); H04N 25/772 (2023.01)
CPC G01J 3/2823 (2013.01) [H01L 27/14621 (2013.01); H01L 27/14627 (2013.01); H04N 25/772 (2023.01)] 20 Claims
OG exemplary drawing
 
1. An image sensor, comprising:
an array of metasurface structures and an array of optical-to-electrical conversion units, wherein the array of metasurface structures is located above the array of optical-to-electrical conversion units; and
a first optical-to-electrical conversion unit in the array of optical-to-electrical conversion units comprises a plurality of optical-to-electrical conversion elements, each optical-to-electrical conversion element in the first optical-to-electrical conversion unit corresponds to one frequency band in a spectrum, a first metasurface structure in the array of metasurface structures comprises a first substrate and a microstructure located above the first substrate, the microstructure and the first substrate are configured to transmit an optical signal at each frequency band to an optical-to-electrical conversion element corresponding to each frequency band, the microstructure is a rotationally symmetric structure, a rotation angle of the rotationally symmetric structure is less than or equal to 90 degrees, and wherein:
the microstructure and the first substrate are configured to generate a spatial transmission phase in a tangential direction of the array of metasurface structures, to obtain a spatial transmission phase gradient, and the spatial transmission phase ϕ(x, y, λn) meets:

OG Complex Work Unit Math
x, y represents coordinates of a position on the first metasurface structure, λn represents a wavelength of an optical signal at an nth frequency band, fn represents a focal length corresponding to the optical signal at the nth frequency band, xf,n and yf,n represent coordinates of a position at which the optical signal at the nth frequency band is transmitted to an optical-to-electrical conversion element corresponding to the nth frequency band, nsub represents a refractive index of a medium between the first metasurface structure and the first optical-to-electrical conversion unit, and C is a phase.