Balancing efficiencies by squeezing in realistic eight-port homodyne detection

Journal Article · Fri Apr 15 04:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.83.043818· OSTI ID:21544704

Pellonpaeae, Juha-Pekka; Schultz, Jussi; Paris, MatteoG A ^[1]

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1. Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland)

We address measurements of covariant phase observables (CPOs) by means of realistic eight-port homodyne detectors. We do not assume equal quantum efficiencies for the four photodetectors and investigate the conditions under which the measurement of a CPO may be achieved. We show that balancing the efficiencies using an additional beam splitter allows us to achieve a CPO at the price of reducing the overall effective efficiency, and prove that it is never a smearing of the ideal CPO achievable with unit quantum efficiency. An alternative strategy based on employing a squeezed vacuum as a parameter field is also suggested, which allows one to increase the overall efficiency in comparison to the passive case using only a moderate amount of squeezing. Both methods are suitable for implementation with current technology.

• OSTI ID: 21544704
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 4 Vol. 83; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
BEAM SPLITTING
DETECTION
EFFICIENCY
PHASE STUDIES
PHOTODETECTORS
QUANTUM EFFICIENCY