Patent ID: 7622704

Claim:
A method for detecting modulated light using an optoelectronic detector, the detector having a photosensitive substrate, at least two readout nodes, and a background illumination node, the method comprising: a. determining a switching sequence, the switching sequence being synchronized with the modulation of the modulated light, the switching sequence comprising periods in which modulated light is present along with background illumination and a period in which background illumination is present; b. activating a light source, the activation leading to impingement of the modulated light on the photosensitive substrate, the impingement resulting in generation of free electron-hole pairs in the photosensitive substrate; c. steering free electrons between the readout nodes according to the switching sequence by generating a potential gradient between the readout nodes; d. steering free electrons to the background illumination node when the background illumination is present; and e. draining free electrons collected at the background illumination node; and f. using the free electrons collected at the at least two readout nodes to detect a phase shift of the modulated light.