Patent ID: 7067793

Claim:
A device, comprising: an InGaAsP photodiode having a bandgap, the photodiode configured to operate in Geiger mode; a first light source configured to emit an optical signal of a first wavelength at a first intensity, the first wavelength less than the bandgap of the photodiode; a second light source configured to emit light of a second wavelength at a second intensity, the second wavelength greater than the bandgap of the photodiode; a beam combiner positioned within an optical path and configured to combine the first and second wavelengths to simultaneously irradiate the photodiode with the first and second wavelengths of light; an electric field applied across the photodiode greater than a breakdown voltage thereof, the electric field configured to result in avalanching of electrons in the photodiode when the optical signal from the first light source is incident thereon, the avalanche of electrons resulting in a photorefractive response within the photodiode; and an image capture device in optical communication with and configured to capture modulated light of the second wavelength reflected from the photodiode.