A concave cell for the collection of radiated light including a body with a concave surface and an unmodified flat surface opposite thereto, and a reflective surface coupled to the body across from the concave surface, said reflective surface including an opening and a photo detector operatively coupled thereto. A method of collecting light by reflecting light inside the concave cell, striking the light at the concave surface, scattering the light at the concave surface, and registering the scattered light with the photo detector. A method of increasing uniformity of light registered in a photo detector. A method of making a concave cell.