System and method for enhancing parasitic light sensitivity of image sensor

An imaging system comprising:

• an imaging controller;
• and
• a camera module comprising:
• a lens system coupled to the imaging controller;
• an image sensor communicatively coupled to the imaging controller and comprising a plurality of image pixels, each image pixel the plurality of image pixels comprising:
• a semiconductor region including a photodiode and a light-sensitive electrical element;
• and
• a primary metalens comprising:
• a dielectric layer;
• and
• a plurality of nanostructures arranged within the dielectric layer, wherein:
• each of the plurality of nanostructures has a first refractive index that is greater than a second refractive index of the dielectric layer;
• and
• the plurality of nanostructures is patterned within the dielectric layer to direct light received by the image pixel away from the light-sensitive electrical element.

A method of operating an image sensor, the method comprising:

• receiving light from a scene at an image pixel of the image sensor;
• diffracting the light, with a primary metalens, into a semiconductor region that includes a photodiode and a light-sensitive electrical element, wherein the primary metalens includes a plurality of nanostructures with a first refractive index arranged in a pattern within a dielectric layer with a second refractive index that is less than the first refractive index;
• directing the light with the primary metalens, based on the pattern of the plurality of nanostructures within the dielectric layer, into a focal area within the semiconductor region that is separate from the light-sensitive electrical element;
• and
• producing an electrical signal with the photodiode responsive to absorption of the light in the semiconductor region.