Systems and methods for imaging using single photon avalanche diodes

1. A single-photon avalanche diode comprising:

a central junction including a central p+ area and a deep-n well in contact with the central p+ area;

a p-type guard ring disposed between the central junction and the deep-n well, at least partially in contact with the central junction; and

a plurality of shallow trench isolations separated from the central p+ area, wherein the p-type guard ring is in contact with a single shallow trench isolation from the plurality of shallow trench isolations proximal to the central junction.

2. The single-photon avalanche diode of claim 1 , further comprising a photosensitive area disposed proximate to the surface of the diode.

3. The single-photon avalanche diode of claim 2 , wherein the photosensitive area has an octagonal shape.

4. The single-photon avalanche diode of claim 1 , wherein the guard ring is configured to substantially surround the p+ area.

5. The single-photon avalanche diode of claim 1 , wherein the guard ring is disposed between the p+ area and the shallow trench isolation.

6. The single-photon avalanche diode of claim 5 , wherein the guard ring is adjacent the p+ area and the shallow trench isolation.

7. An imaging apparatus, comprising:

a plurality of pixels, each pixel comprising:

a complementary metal-oxide-semiconductor-implemented single photon avalanche diode, the single photon avalanche diode comprising

a central junction including a central p+ area and a deep-n well in contact with the central p+ area,

a p-type guard ring disposed between the central junction and the deep-n well, at least partially in contact with the central junction, and

a plurality of shallow trench isolations separated from the central p+ area, wherein the p-type guard ring is in contact with a single shallow trench isolation from the plurality of shallow trench isolations proximal to the central junction; and

one or more signal converters electrically coupled to the diode and configured to detect changes in output therefrom.

8. The apparatus of claim 7 , wherein the one or more signal converters comprise delay-locked loop-based time-to-digital converters.

9. The apparatus of claim 7 , each single photon avalanche diode further comprising a quenching circuit and a resetting circuit connected in series with the single photon avalanche diode.

10. The apparatus of claim 9 , wherein the quenching circuit further comprises a resistive component.

11. The apparatus of claim 10 , wherein the resistive component further comprises a variable resistor.

12. The apparatus of claim 10 , wherein the resistive component further comprises a resistor.

13. The apparatus of claim 9 , wherein the single photon avalanche diodes are arranged in an array.

14. The apparatus of claim 13 , wherein the array further comprises a two-dimensional 64 * 64 array.

15. The apparatus of claim 13 , wherein the array further comprises a two-dimensional 128 * 128 array.

16. The apparatus of claim 9 , wherein the signal converters are further coupled to a processor configured to compress data.

17. The apparatus of claim 9 , wherein the apparatus is configured to detect a signal categorized as a non-homogeneous Poisson process.

18. The apparatus of claim 9 , further comprising a C-mount adapter disposed proximate to the surface of the apparatus, enabling it to connect to a microscope.

19. The apparatus of claim 7 , wherein the resetting circuit further comprises an active resetting circuit.

20. A laser scanning microscopy system comprising the imaging apparatus of claim 7 .

21. A two-photon microscopy system comprising the imaging apparatus of claim 7 .

22. An endoscopic imaging system comprising the imaging apparatus of claim 7 .