Meta-optical device and optical apparatus including the same

1. A meta-optical device comprising:

a meta-lens comprising a plurality of concentric regions and a plurality of nano-structures arranged two-dimensionally in the plurality of concentric regions, each of the plurality of nano-structures having a pillar shape of which cross section is circular, elliptical or polygonal;

a band pass filter configured to transmit light of predetermined wavelengths within an operation wavelength band of the meta-lens;

a spacer layer provided between the meta-lens and the band pass filter, the spacer layer supporting the plurality of nano-structures and providing a separation distance between the meta-lens and the band pass filter; and

a refractive lens having a flat surface and a curved surface,

wherein the plurality of nano-structures are provided the flat surface side of the refractive lens.

2. The meta-optical device of claim 1 , wherein the meta-lens, the spacer layer, and the band pass filter are integrally formed on a substrate.

3. The meta-optical device of claim 1 , wherein a thickness of the spacer layer is greater than a center wavelength ko of the operation wavelength band of the meta-lens and is smaller than 30 λo.

4. The meta-optical device of claim 1 , wherein the band pass filter is an infrared cut-off filter.

5. The meta-optical device of claim 1 , wherein the band pass filter is a color filter array comprising a red filter, a green filter, and a blue filter.

6. The meta-optical device of claim 1 , wherein the band pass filter comprises at least one of a red filter, a green filter, and a blue filter.

7. The meta-optical device of claim 1 , further comprises a protection layer provided on the plurality of nano-structures opposite to the spacer layer, a refractive index of the protection layer being less than a refractive index of the plurality of nano-structures.

8. The meta-optical device of claim 7 , further comprises a plurality of second nano-structures two-dimensionally arranged on the protection layer.

9. An image capturing apparatus comprising:

a lens assembly comprising a refractive lens that has a flat surface and a curved surface;

a meta-optical device comprising:

a meta-lens comprising a plurality of concentric regions and a plurality of nano-structures arranged two-dimensionally in the plurality of concentric regions, each of the plurality of nano-structures having a pillar shape of which cross section is circular, elliptical or polygonal;

a band pass filter configured to transmit light of predetermined wavelengths within an operation wavelength band of the meta-lens; and

a spacer layer provided between the meta-lens and the band pass filter, the spacer layer supporting the plurality of nano-structures and providing a separation distance between the meta-lens and the band pass filter;

a protection layer provided on the plurality of nano-structures opposite to the spacer layer, a refractive index of the protection layer being less than a refractive index of the plurality of nano-structures; and

an image sensor configured to convert an optical image formed by the lens assembly and the meta-optical device into an electrical signal,

wherein the plurality of nano-structures are provided on the flat surface side of the refractive lens.

10. The image capturing apparatus of claim 9 , wherein a thickness of the spacer layer is greater than a center wavelength λo of the operation wavelength band of the meta-lens and is smaller than 30 λo.

11. The image capturing apparatus of claim 9 , wherein the meta-lens, the spacer layer, and the band pass filter are integrally formed on a substrate.

12. The image capturing apparatus of claim 11 , wherein the band pass filter is an infrared cut-off filter.

13. The image capturing apparatus of claim 12 , wherein the meta-optical device is provided between the lens assembly and the image sensor.

14. The image capturing apparatus of claim 11 , wherein the substrate is a cover glass for the image sensor.

15. The image capturing apparatus of claim 11 , wherein the band pass filter is a color filter array comprising a red filter, a green filter, and a blue filter.

16. The image capturing apparatus of claim 15 , wherein the meta-lens comprises:

a first meta-lens facing the red filter and configured to focus red light;

a second meta-lens facing the green filter and configured to focus green light; and

a third meta-lens facing the blue filter and configured to focus blue light.

17. The image capturing apparatus of claim 16 , wherein the lens assembly comprises:

a first lens assembly facing the first meta-lens;

a second lens assembly facing the second meta-lens; and

a third lens assembly facing the third meta-lens.

18. The image capturing apparatus of claim 17 , wherein the meta-optical device is provided between the lens assembly and the image sensor.

19. The image capturing apparatus of claim 9 , wherein the band pass filter comprises at least one of a red filter, a green filter, and a blue filter.

20. The image capturing apparatus of claim 19 , wherein the band pass filter, the spacer layer, and the meta-lens are integrally formed on a substrate.

21. The image capturing apparatus of claim 20 , wherein the meta-optical device is provided between the lens assembly and the image sensor.

22. A meta-optical device comprising:

a refractive lens having two surfaces opposite to each other, one of the two surfaces being a flat surface and the other of the two surfaces being a curved surface;

an infrared cut-off filter disposed on the flat surface;

a spacer layer on the infrared cut-off filter; and

a meta-lens disposed on the spacer layer and comprising a plurality of nano-structures, the plurality of nano-structures being provided on the flat surface side of the refractive lens.