Time Correlated Photons using Optical Rephasing Techniques with Rare Earth Ion

Doped Solids

Patrick Ledingham and Jevon LongdellJack Dodd Centre for Quantum Technology, Physics Dept., The University of Otago, New Zealand

QIP-REIDS 2011

Two Pulse Photon Echo

High EfficiencyTemporally Multimode

Broadband

Quantum Memory for Light

Two Pulse Photon Echo

Collective Spontaneous Emission

2PE ≠ QM

1. Rephased Amplified Spontaneous Emission

2. Experimental Results

Outline

Rephased Amplified Spontaneous Emission

RASE violates Cauchy –Swartz Inequality

Rephased Amplified Spontaneous Emission

RASE = broadband time entangled photon streams

InterferometerExperimental Set Up

Sample Balanced Heterodyne Detection

ECDL

Hybrid Locking to a

Spectral Hole

Two Pulse Photon Echo

Optical Depth = 3.1

Efficiency @ Zero Delay= 190%

T2 = ~ 20μs

Amplified Spontaneous Emission

2500 shots at 10Hzπ/2, π, 3π/2, 2πtπ = 1.6μs

Amplified Spontaneous Emission

Bandwidth of ASE= 170kHz

Amplified Spontaneous Emission

ASE is phase independent

Rephased Amplified Spontaneous Emission

55μs

100μs

20μs

Cross-Correlation

6.44μs

60μs

10μs20μs

Cross-Correlation

3.5μs

Is it Quantum?

Inseparability Criterion

Not Quantum, why?

•Imperfect π pulses

•Detection Mode

Conclusion

• Rephased Amplified Spontaneous Emission is a protocol to create broadband time separated entangled photons

• Measured a correlation between the ASE and RASE fields – not quantum, yet

60μs

10μs20μs

Rephased Amplified Spontaneous Emission

Detection Mode