Patent ID: 6342720
Filing Date: 2002-01-29
Classification: B82Y,H01L,Y02E

Abstract:
A voltage-controlled wavelength-selective photodetector comprising:a first detector including a Schottky diode, the first detector tuned to a first range of wavelengths, the first range of wavelengths including a noise component, the first detector having a first contact, the first contact being at a first potential; and a second detector including a Si/SiGe pn diode or a PIN diode, the second detector tuned to a second range of wavelengths, the second range of wavelengths different from the first range of wavelengths, the second range of wavelengths including a useful signal, the second detector having a second contact, the second contact being at a second potential, the first and second detectors being disposed one on top of the other, the first potential and the second potential defining a potential difference; wherein a first photoelectric current induced in the first detector by incident light in the first range of wavelengths corresponding to the noise component is subtracted from a second photoelectric current induced in the second detector by incident light in the second range of wavelengths corresponding to the useful signal, thereby filtering out the noise component from the useful signal.