Patent ID: 8441032

Claim:
A Geiger-mode detector device operable for detecting a low-level input signal, the device comprising: at least one compound semiconductor layer configured to provide an avalanche p-n or p-i-n junction; a first electrically conductive electrode and a second electrically conductive electrode operable to provide a voltage bias across said avalanche p-n or p-i-n junction; a composite dielectric layer disposed between one of said first and second electrodes and the at least one compound semiconductor layer; wherein the device is configured to be operable in a Geiger mode such that with said voltage bias biasing the avalanche p-n or p-i-n junction in or above the breakdown region said composite dielectric layer provides negative feedback for quenching the avalanche process predominantly through capacitive feedback; and wherein the at least one compound semiconductor layer comprises (i) a photoabsorption region sensitive to a photon having a wavelength of at least about 950 nm or greater, the Geiger-mode detector device thereby being implemented as a Geiger-mode avalanche photodiode (APD) device, and (ii) an avalanche multiplication region that is separate from the photoabsorption region.