Photodetector array on curved substrate

A method, comprising:

• transmitting, by a plurality of light sources, light through an optical system into an environment, wherein each light source in the plurality of light sources is paired with a corresponding photodetector in a plurality of photodetectors;
• and
• receiving, by the optical system, light that has been transmitted by a light source in the plurality of light sources and reflected by an object in the environment;
• focusing, by the optical system, the received light onto the light source's corresponding photodetector in the plurality of photodetectors, wherein the optical surface defines a focal surface having a curved shape, wherein the photodectors are mounted on a flexible substrate, and wherein the flexible substrate is held by a holder such that the flexible substrate substantially conforms to the curved shape of the focal surface and each of photodetectors in the plurality of photodetectors is at a respective location on the focal surface.