Narrowband Source of Single Photons for a Quantum Repeater
Sonali Gera a *, Steven Sagona-Stophel a, Mael Flament, Alessia Scriminich, Mehdi Namazi and Eden Figueroa a *
a Stony Brook University, New York, USA
Components of a Quantum Repeater Potable Versions
❑ Four Quantum Memories
❑ Two Sources❑ Storage of
Entanglement❑ Measurement
Station
Preparation of pulses to be stored in memories.
Hong-Ou-Mandel Interference of retrieved single photon level pulses
We use Down Conversion in non-linear crystals
P = 𝜀𝜒𝐸. Linear
P = Higher order terms in E Non-linear
E^2 term generates light of frequency different from input frequency
Probability of Down conversion ~ 10-5 Too Low!
Place the crystal inside a cavity!!
Some Enhancement is needed!
Source of Photon Pairs
Cavity narrows bandwidth
To lock cavity lengthSet Up
Master Laser locked to atomic transition (D1 line of Rb)Second Harmonic Generation; for pump productionBow Tie Cavity with Type 1 PPKTP crystal
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2
3
Pound Drever Hall Lock to maintain cavity length to have down converted photons resonant to the cavityFrequency Lock to have Locking laser 3FSR away from 795nm.
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5
OPA Output : Down converted photons while the OPA is scanned. Before filtering(right, top) and after filtering(right, middle). Bottom :795nm laser as a reference.
Expected Pair Production Rate :5-6KHz for 5mW of Pump.
Results
Combining the source with the memories Connecting Stony Brook University and BNL on Long Island.
Future Work
Phase matching bandwidth ~ 60GHzFSR = 300MHz
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