SYSTEMS AND METHODS FOR IMAGING USING SINGLE PHOTON AVALANCHE DIODES
Single-photon avalanche diode includes a central junction having 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, and a shallow trench isolation separated from the central p+ area. Imaging apparatus includes a plurality of pixels, each pixel comprising a complementary metal-oxide-semiconductor-implemented single photon avalanche device and one or more signal converters electrically coupled thereto and configured to detect changes in output therefrom.
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; and
a shallow trench isolation separated from the central p+ area.
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 . An imaging apparatus, comprising:
a plurality of pixels, each pixel comprising a complementary metal-oxide-semiconductor-implemented single photon avalanche device and one or more signal converters electrically coupled thereto and configured to detect changes in output therefrom.
7 . The apparatus of claim 6 , wherein the one or more signal converters comprise delay-locked loop-based time-to-digital converters.
8 . The apparatus of claim 6 , each single photon avalanche diode further comprising a quenching circuit and a resetting circuit connected in series with the single photon avalanche diode.
9 . The apparatus of claim 8 , wherein the quenching circuit further comprises a resistive component.
10 . The apparatus of claim 9 , wherein the resistive component further comprises a variable resistor.
11 . The apparatus of claim 9 , wherein the resistive component further comprises a resistor.
12 . The apparatus of claim 6 , wherein the resetting circuit further comprises an active resetting circuit.
13 . The apparatus of claim 8 , 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 8 , wherein the signal converters are further coupled to a processor configured to compress data.
17 . The apparatus of claim 8 , wherein the apparatus is configured to detect a signal categorized as a non-homogeneous Poisson process
18 . The apparatus of claim 8 , further comprising a C-mount adapter disposed proximate to the surface of the apparatus, enabling it to connect to a microscope.
19 . A laser scanning microscopy system comprising the imaging apparatus of claim 6 .
20 . A two-photon microscopy system comprising the imaging apparatus of claim 6 .
21 . An endoscopic imaging system comprising the imaging apparatus of claim 6 .