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Updated: Jun 2, 2026
09:23
Quantum State Engineering of Light with Continuous-wave Optical Parametric Oscillators
Published on: May 30, 2014
Photon echo without a free induction decay in a double-Λ system.
Sarah E Beavan1, Patrick M Ledingham, Jevon J Longdell
1Laser Physics Centre, Research School of Physics & Engineering, Australian National University, Canberra, ACT 0200, Australia. sarah.beavan@anu.edu.au
Optics Letters
|April 12, 2011
Summary
We developed a new photon-echo pulse sequence for quantum systems. This technique significantly reduces noise, enabling efficient generation of entangled photon pairs with distinct properties.
Area of Science:
- Quantum optics
- Atomic physics
- Spectroscopy
Background:
- Photon-echo techniques are crucial for studying light-matter interactions.
- Double-Λ energy level systems are fundamental in quantum information processing.
- Free induction decay (FID) introduces significant noise in optical experiments.
Purpose of the Study:
- To characterize a novel photon-echo pulse sequence for a double-Λ energy level system.
- To evaluate the noise reduction capabilities of the new sequence compared to FID.
- To assess the potential of this sequence for generating entangled photon pairs within the RASE scheme.
Main Methods:
- Implementation of a novel photon-echo pulse sequence with distinct input/rephasing transitions.
- Characterization of noise levels in echo mode versus FID modes.
- Evaluation of coherence and efficiency in a Pr(3+):Y₂SiO₅ crystal.
- Application of the sequence within the rephased amplified spontaneous emission (RASE) scheme.
Main Results:
- The novel sequence achieved exceptionally low noise: 0.2 ± 0.1 photons per shot in echo mode.
- This represents a significant reduction compared to 4 × 10⁴ photons in FID modes.
- Coherence and efficiency properties were successfully characterized in the Pr(3+):Y₂SiO₅ crystal.
Conclusions:
- The developed photon-echo pulse sequence offers superior noise suppression for quantum applications.
- This technique facilitates the generation of multi-mode entangled photon pairs via the RASE scheme.
- The findings have implications for advanced quantum communication and computation.
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