Apparatus comprising a single photon photodetector having reduced afterpulsing and method therefor
View Patent ↗A single-photon detector is disclosed that provides reduced afterpulsing without some of the disadvantages for doing so in the prior art. An embodiment of the present invention provides a stimulus pulse to the active area of an avalanche photodetector to stimulate charges that are trapped in energy trap states to detrap. In some embodiments of the present invention, the stimulus pulse is a thermal pulse.
1. A method comprising providing a stimulating pulse to an avalanche photodetector, wherein the stimulating pulse is provided after the avalanche photodetector has been quenched and while the avalanche photodetector is biased below a breakdown voltage, and wherein the stimulating pulse is suitable for detrapping electrical carriers in the avalanche photodetector.
2. The method of claim 1 further comprising biasing the avalanche photodetector above the breakdown voltage after detrapping the electrical carriers.
3. The method of claim 1 wherein the stimulating pulse is applied to the avalanche photodetector after the detection of at least one of a photon and a dark carrier by the avalanche photodetector.
4. The method of claim 1 wherein the stimulating pulse is applied to the avalanche photodetector on a periodic basis.
5. The method of claim 1 further comprising gating the avalanche photodetector with a gating pulse.
6. A method comprising:
quenching an avalanche photodetector;
detrapping electrical carriers within the avalanche photodetector, wherein the detrapping comprises providing a stimulating pulse to the avalanche photodetector.
7. The method of claim 6 further comprising arming the avalanche photodetector after detrapping.
8. The method of claim 7 wherein the avalanche photodetector is armed by a controller, and wherein the controller arms the avalanche photodetector in response to at least one of:
i) receipt of a stimulus by the controller;
ii) satisfaction of a preset condition; and
iii) a signal from an operator.
9. The method of claim 6 wherein the quenching occurs after the detection of at least one of a photon and a dark carrier.
10. The method of claim 6 wherein providing the stimulating pulse during the detrapping operation comprises providing a thermal pulse.
11. The method of claim 10 wherein the thermal pulse is radiated to the avalanche photodetector.
12. The method of claim 10 wherein providing the thermal pulse comprises applying an electric current to the avalanche photodetector.
13. The method of claim 10 wherein providing the thermal pulse comprises applying an electric current to a heater, and wherein the heater and the avalanche photodetector are monolithically-integrated.
14. The method of claim 10 wherein providing the thermal pulse comprises applying a pulse of optical energy to the avalanche photodetector.
15. The method of claim 14 wherein the photodetector comprises a multiplication region, and wherein the multiplication region is characterized by a bandgap energy, and further wherein the optical energy is characterized by having photon energy that is equal to or larger than the bandgap energy.
16. The method of claim 15 wherein the optical energy is characterized by a wavelength of less than or equal to 900 nanometers.