Aperture-metasurface and hybrid refractive-metasurface imaging systems
Hybrid imaging systems incorporating conventional optical elements and metasurface elements with light sources and/or detectors, and methods of the manufacture and operation of such optical arrangements are provided. Systems and methods describe the integration of apertures with metasurface elements and refractive optics with metasurface elements in illumination sources and sensors.
1. An imaging system comprising:
at least one image sensor;
a substrate layer having a substrate thickness, the substrate layer configured to be transparent to a target wavelength of light, the substrate layer having a first surface distal the at least one image sensor and a second surface proximal with the at least one image sensor;
a spacer layer creating an airgap between the second surface of the substrate and the image sensor; and
a metasurface comprising a single layer of a plurality of identical or unique nanostructured elements disposed on one of either the first or second surfaces, such that light passes through at least a portion of the nanostructured elements such that an angular deflection is imposed thereby,
wherein the metasurface is configured to gather light of a specified operational bandwidth across a specified field of view and shift incoming light such that it focuses on the at least one image sensor at a zero or near-zero degree chief ray angle,
wherein the image sensor and the metasurface have rectangular geometries in plan view, and
wherein the rectangular metasurface is configured to create a rectangular image of the specified field of view onto the rectangular image sensor.
2. The imaging system of claim 1 , wherein the metasurface is disposed on the first surface.
3. The imaging system of claim 2 , further comprising a narrow bandwidth optical filter disposed on the second surface between the nanostructured elements and the at least one image sensor.
4. The imaging system of claim 2 , wherein the image sensor is in contact with the spacer layer.
5. The imaging system of claim 1 , wherein the metasurface is disposed on the second surface.
6. The imaging system of claim 1 , wherein the field of view is at least ±30 degrees.
7. An imaging system comprising:
at least one image sensor;
a substrate layer having a substrate thickness, the substrate layer configured to be transparent to a target wavelength of light, the substrate layer having a first surface distal the at least one image sensor and a second surface proximal with the at least one image sensor;
at least one refractive lens disposed above the substrate and configured to focus impinging light on the first surface of the substrate layer; and
a single layer of a plurality of identical or unique nanostructured elements comprising a metasurface disposed on one of either the first or second surfaces, such that light impinging on the at least one refractive lens passes through at least a portion of the nanostructured elements such that an angular deflection is imposed thereby,
wherein the distance between the at least one refractive lens and the metasurface are separated by a first distance,
wherein the refractive lens and the metasurface are configured to gather light of a specified operational bandwidth across a specified field of view and shift incoming light such that it focuses on the at least one image sensor at a zero or near-zero degree chief ray angle,
wherein at least the imaging sensor and metasurface have rectangular geometries,
wherein the image sensor is characterized by a vertical, v, and a horizontal, h, dimension, and wherein the at least one refractive lens is characterized by a f-number of the at least one refractive lens, N, defined as N=f/D where f is a focal length of the imaging system and D is a diameter of the at least one refractive lens, and
wherein a metasurface width is given by:
w=v+f/N , and
wherein a metasurface length I is given by:
l=h+f/N.
8. The imaging system of claim 7 , wherein the at least one refractive lens is selected from the group consisting of plano-convex, convex-plano, bi-convex, bi-concave, plano-concave, or concave-plano.
9. The imaging system of claim 7 , wherein at least a portion of at least one of the refractive lens is interconnected with the first surface.
10. The imaging system of claim 7 , wherein the at least one refractive lens comprises at least two refractive lenses comprising a convex-concave lens and concave-convex lens.
11. The imaging system of claim 7 , wherein the at least one refractive lens comprises at least two refractive lenses comprising a convex-concave lens, a bi-convex lens, and/or a concave-plano lens.
12. The imaging system of claim 7 , wherein the at least one refractive lens has a circular geometry.