dorsal/arxiv
View SchemaAll-optical versus electro-optical quantum-limited feedback
| Authors | H. M. Wiseman, G. J. Milburn |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0409050 |
| URL | https://arxiv.org/abs/quant-ph/0409050 |
| DOI | 10.1103/PhysRevA.49.4110 |
| Journal | Phys. Rev. A 49, 4110 (1994) |
Abstract
All-optical feedback can be effected by putting the output of a source cavity through a Faraday isolator and into a second cavity which is coupled to the source cavity by a nonlinear crystal. If the driven cavity is heavily damped, then it can be adiabatically eliminated and a master equation or quantum Langevin equation derived for the first cavity alone. This is done for an input bath in an arbitrary state, and for an arbitrary nonlinear coupling. If the intercavity coupling involves only the intensity (or one quadrature) of the driven cavity, then the effect on the source cavity is identical to that which can be obtained from electro-optical feedback using direct (or homodyne) detection. If the coupling involves both quadratures, this equivalence no longer holds, and a coupling linear in the source amplitude can produce a nonclassical state in the source cavity. The analogous electro-optic scheme using heterodyne detection introduces extra noise which prevents the production of nonclassical light. Unlike the electro-optic case, the all-optical feedback loop has an output beam (reflected from the second cavity). We show that this may be squeezed, even if the source cavity remains in a classical state.
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"abstract": "All-optical feedback can be effected by putting the output of a source cavity\nthrough a Faraday isolator and into a second cavity which is coupled to the\nsource cavity by a nonlinear crystal. If the driven cavity is heavily damped,\nthen it can be adiabatically eliminated and a master equation or quantum\nLangevin equation derived for the first cavity alone. This is done for an input\nbath in an arbitrary state, and for an arbitrary nonlinear coupling. If the\nintercavity coupling involves only the intensity (or one quadrature) of the\ndriven cavity, then the effect on the source cavity is identical to that which\ncan be obtained from electro-optical feedback using direct (or homodyne)\ndetection. If the coupling involves both quadratures, this equivalence no\nlonger holds, and a coupling linear in the source amplitude can produce a\nnonclassical state in the source cavity. The analogous electro-optic scheme\nusing heterodyne detection introduces extra noise which prevents the production\nof nonclassical light. Unlike the electro-optic case, the all-optical feedback\nloop has an output beam (reflected from the second cavity). We show that this\nmay be squeezed, even if the source cavity remains in a classical state.",
"arxiv_id": "quant-ph/0409050",
"authors": [
"H. M. Wiseman",
"G. J. Milburn"
],
"categories": [
"quant-ph"
],
"doi": "10.1103/PhysRevA.49.4110",
"journal_ref": "Phys. Rev. A 49, 4110 (1994)",
"title": "All-optical versus electro-optical quantum-limited feedback",
"url": "https://arxiv.org/abs/quant-ph/0409050"
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