Schematics of the setup used to study single-photon vision.

Schematic of the setup for generating single photons via spontaneous parametric down-conversion (SPDC). Light stimuli are triggered (T) by subjects and coupled into a single-mode fiber entering the dark chamber. The light is directed and focused onto the pupil (Maxwellian view) at an angle of 23ᵒ temporal to a highly attenuated red fixation light presented at the fovea. ND, neutral density filter, L, lens, SPAD, single-photon avalanche detector. F, bandpass and spatial filter, HWP, half-wave-plate, PBS, polarizing beam-splitter, BBO, beta barium borate crystal, EMCCD, electron-multiplying charge-coupled device. A flip mirror (FM) allowed for the switching of the detection mechanism from the EMCCD to a SPAD.

Schematics of the setup used to study single-photon vision.