Apparatus and methods for single photon sources

Patent metadata

Field	Value
Publication number	US-9798219-B2
Application number	US-201615172747-A
Country	US
Kind code	B2
Filing date	Jun 3, 2016
Priority date	Jun 3, 2015
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

A photon source to deliver single photons includes a storage ring resonator to receive pump photons and generate a signal photon and an idler photon. An idler resonator is coupled to the storage resonator to couple the idler photon out of the storage resonator and into a detector. Detection of the idler photon stops the pump photons from entering the storage resonator. A signal resonator is coupled to the storage resonator to couple out the signal photon remaining in the storage resonator and delivers the signal photon to applications. The photon source can be fabricated into a photonic integrated circuit to achieve high compactness, reliability, and controllability.

First claim

The invention claimed is:

1. A single-photon source comprising:
a storage resonator to receive pump photons from a photon source at a pump frequency ω P and to generate a signal photon at a signal frequency ω s and an idler photon at an idler frequency ω i from the pump photons, wherein the signal frequency ω s is different than the idler frequency ω i ;
a detector, operably coupled to the storage resonator, to detect the idler photon and to generate a control signal in response to detection of the idler photon;
a switch, operably coupled to the detector and optically coupled to the storage resonator, to prevent transmission, in response to the control signal, and to allow transmission, in response to a clock signal, of subsequent pump photons from the photon source to the storage resonator; and
a signal resonator, optically coupled to the storage resonator, to receive the signal photon out of the storage resonator and, in response to the clock signal, to couple the signal photon into an output coupler.

2. The single-photon source of claim 1 , wherein the storage resonator comprises a ring resonator.

3. The single-photon source of claim 1 , wherein the storage resonator is configured to resonate at the signal frequency ω s .

4. The single-photon source of claim 1 , further comprising:
a pump resonator, optically coupled between the switch and the storage resonator, to couple the pump photons from the photon source into the storage resonator, wherein the pump resonator is configured to resonate at the pump frequency ω P .

5. The single-photon source of claim 1 , further comprising:
an idler resonator, optically coupled between the storage resonator and the detector, to couple the idler photon from the storage resonator to the detector, wherein the idler resonator is configured to resonate at the idler frequency ω i .

6. The single-photon source of claim 1 , wherein the signal resonator, upon receiving the clock signal, is configured to resonate at the signal frequency ω s so as to couple the signal photon out of the storage resonator.

7. The single-photon source of claim 1 , wherein the photon source comprises:
a laser source, in optical communication with the switch, to provide the pump photons.

8. The single-photon source of claim 1 , further comprising:
a clock signal generator, operably coupled to the signal resonator, to generate the clock signal.

9. The single-photon source of claim 1 , wherein the pump frequency ω P , the signal frequency ω s , and the idler frequency ω i are correlated according to ω s +ω i =2ω P .

10. The single-photon source of claim 1 , wherein the storage resonator and the output coupler are fabricated in a semiconductor substrate.

11. A method of delivering single photons, the method comprising:
A) coupling at least two pump photons at a pump frequency from a photon source to a storage resonator;
B) generating a signal photon at a signal frequency and an idler photon at an idler frequency different than the signal frequency in the storage resonator from the at least two pump photons;
C) detecting the idler photon with a detector;
D) preventing transmission of subsequent pump photons from the photon source to the storage resonator in response to detection of the idler photon in C); and
E) coupling the signal photon out of the storage resonator in response to a clock signal.

12. The method of claim 11 , wherein A) comprises coupling the at least two pump photons into a ring resonator.

13. The method of claim 11 , wherein A) comprises:
A1) receiving the at least two pump photons from a photon source using a pump resonator resonating at the pump frequency; and
A2) coupling the at least two pump photons from the pump resonator to the storage resonator.

14. The method of claim 13 , further comprising:
after C) and before E), coupling at least one remaining pump photon out of the storage resonator via the pump resonator.

15. The method of claim 11 , wherein B) comprises generating the signal photon and the idler photon via a degenerate four wave mixing process.

16. The method of claim 11 , wherein C) further comprises:
C1) coupling the idler photon to an idler resonator resonating at the idler frequency; and
C2) transmitting the idler photon from the idler resonator to the detector.

17. The method of claim 11 , wherein the detector comprises a single photon detector (SPD).

18. The method of claim 11 , wherein E) comprises:
E1) transmitting the clock signal to a signal resonator, optically coupled to the storage resonator, so as to cause the signal resonator to resonate at the signal frequency; and
E2) coupling the signal photon out of the storage resonator via the signal resonator.

19. The method of claim 18 , further comprising:
removing the clock signal so as to cause the signal resonator to stop resonating at the signal frequency.

20. An apparatus to deliver single photons, the apparatus comprising:
a pump ring resonator to receive pump photons at a pump frequency ω P from a photon source, wherein the pump resonator is configured to resonate at the pump frequency ω P ;
a storage ring resonator, optically coupled to the pump ring resonator, to receive the pump photons from the pump ring resonator and to generate a signal photon at a signal frequency ω s and an idler photon at an idler frequency ω i different than the signal frequency ω s , wherein the storage ring resonator is configured to resonate at the signal frequency ω s ;
an idler ring resonator, optically coupled to the storage ring resonator, to receive the idler photon generated in the storage ring resonator, wherein the idler ring resonator is configured to resonate at the idler frequency ω i ;
a photon detector, optically coupled to the idler ring resonator, to detect the idler photon from the idler ring resonator and to generate a control signal in response to detection of the idler photon;
a switch, operably coupled to the photon detector and optically coupled to the pump ring resonator, to prevent transmission, in response to the control signal, and to allow transmission, in response to a clock signal, of subsequent pump photons from the photon source to the pump ring resonator; and
a signal ring resonator, optically coupled to the storage ring resonator, to resonate at the signal frequency ω s in response to the clock signal and to couple the signal photon out of the storage ring resonator.

Assignees

• Pant Mihir
• Englund Dirk Robert
• Heuck Mikkel
• Massachusetts Inst Technology

Inventors

• Pant Mihir
• Englund Dirk Robert
• Heuck Mikkel

Classifications

• G02F1/31 Primary

  Digital deflection, {i.e. optical switching}(G02F1/33 takes precedence) · CPC title

• G02F1/3501

  Constructional details or arrangements of non-linear optical devices, e.g. shape of non-linear crystals · CPC title

• H04B10/70

  Photonic quantum communication · CPC title

• G02F1/39

  for parametric generation or amplification of light, infrared or ultraviolet waves · CPC title

• G02F1/3536

  Four-wave interaction · CPC title