Phototransistor capable of detecting photon flux below photon shot noise

1. A phototransistor (PT) comprising an emitter, a collector and a floating base, wherein the PT is configured to detect a photon flux incident on the PT and the photon flux being lower than one single photon within an electrical bandwidth of the PT.

2. A phototransistor (PT) comprising an emitter, a collector and a floating base, wherein the PT is configured to detect a photon flux incident on the PT and the photon flux being below a photon shot noise of the photon flux within an electrical bandwidth of the PT.

3. The PT of claim 2 , wherein the photon flux is 1/√{square root over (β)} of a photon shot noise of the photon flux within an electrical bandwidth of the PT, wherein β is a current amplification gain of the PT.

4. A phototransistor (PT) comprising an emitter, a collector and a floating base, wherein the PT is configured to detect a photon flux incident on the PT and the photon flux being below 2f, wherein f is an electrical bandwidth of the PT.

5. The PT of claim 4 , wherein the photon flux is 2f/β, wherein f is an electrical bandwidth of the PT and β is a current amplification gain of the PT.

6. The PT of claim 1 , wherein a junction between the emitter and the floating base, the base and a junction between the collector and the floating base are in direct physical contact only with and completely encapsulated only by the emitter, a dielectric, and the collector.

7. The PT of claim 2 , wherein a junction between the emitter and the floating base, the base and a junction between the collector and the floating base are in direct physical contact only with and completely encapsulated only by the emitter, a dielectric, and the collector.

8. The PT of claim 4 , wherein a junction between the emitter and the floating base, the base and a junction between the collector and the floating base are in direct physical contact only with and completely encapsulated only by the emitter, a dielectric, and the collector.

9. A method of detecting a photon signal, the method comprising receiving a photon flux with the PT of claim 1 under a non-zero bias voltage and reading an electrical current at the emitter or the collector.

10. A method of detecting a photon signal, the method comprising receiving a photon flux with the PT of claim 2 under a non-zero bias voltage and reading an electrical current at the emitter or the collector.

11. A method of detecting a photon signal, the method comprising receiving a photon flux with the PT of claim 4 under a non-zero bias voltage and reading an electrical current at the emitter or the collector.

12. An apparatus, comprising

an optical system having an image plane or a focal plane;

an array of PTs of claim 2 positioned on the image plane or focal plane.

13. A method of detecting an object, the method comprising

directing light from the object onto the PT of claim 2 ;

detecting a current at the collector of the PT, at the emitter of the PT, or between the collector and the emitter of the PT;

determining a photon flux of the light directed onto the PT;

wherein the photon flux of the light is lower than a photon shot noise of the photon flux within an electrical bandwidth of the PT.

14. An Adaptive Optics (AO) system, comprising the PT of claim 2 .

15. A Light Detection And Ranging (LIDAR) system, comprising the PT of claim 2 .