skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Quantum limits on noise in dual input-output linear optical amplifiers and attenuators

Abstract

The input-output relations for linear amplifiers and attenuators that have two input and two output channels are used to derive inequalities that relate their gain profiles and output noise spectra. The results generalize earlier derivations, which mainly focus their attention on single-channel devices, to the two-ended amplifiers and attenuators often used in practical communications systems. The present inequalities are satisfied by the results of previous calculations for specific model systems. It is shown that; in contrast to single-channel devices, a two-ended system can act as an amplifier for some input signals and an attenuator for others, even when all the signal frequencies are the same. The output from the two-channel amplifier has a minimum noise determined by the sum of the gains for both input channels, even when only one input channel is used and the other is in its vacuum state. The conditions on device construction needed to achieve equal gains for signals that arrive at the two ends of the device are determined. The present results reduce to those of single-channel theory in special cases where the two output channels are each separately fed by only one of the two input channels.

Authors:
;  [1]; ;  [2]
  1. Department of Electronic Systems Engineering, University of Essex, Colchester CO4 3SQ (United Kingdom)
  2. Department of Physics, University of Strathclyde, Glasgow G4 0NG, Scotland (United Kingdom)
Publication Date:
OSTI Identifier:
20633879
Resource Type:
Journal Article
Journal Name:
Physical Review. A
Additional Journal Information:
Journal Volume: 67; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevA.67.033803; (c) 2003 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1050-2947
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; AMPLIFIERS; DATA TRANSMISSION; GAIN; NOISE; OPTICS; QUANTUM MECHANICS; SIGNALS; VACUUM STATES

Citation Formats

Loudon, Rodney, Jedrkiewicz, Ottavia, Barnett, Stephen M, and Jeffers, John. Quantum limits on noise in dual input-output linear optical amplifiers and attenuators. United States: N. p., 2003. Web. doi:10.1103/PhysRevA.67.033803.
Loudon, Rodney, Jedrkiewicz, Ottavia, Barnett, Stephen M, & Jeffers, John. Quantum limits on noise in dual input-output linear optical amplifiers and attenuators. United States. https://doi.org/10.1103/PhysRevA.67.033803
Loudon, Rodney, Jedrkiewicz, Ottavia, Barnett, Stephen M, and Jeffers, John. Sat . "Quantum limits on noise in dual input-output linear optical amplifiers and attenuators". United States. https://doi.org/10.1103/PhysRevA.67.033803.
@article{osti_20633879,
title = {Quantum limits on noise in dual input-output linear optical amplifiers and attenuators},
author = {Loudon, Rodney and Jedrkiewicz, Ottavia and Barnett, Stephen M and Jeffers, John},
abstractNote = {The input-output relations for linear amplifiers and attenuators that have two input and two output channels are used to derive inequalities that relate their gain profiles and output noise spectra. The results generalize earlier derivations, which mainly focus their attention on single-channel devices, to the two-ended amplifiers and attenuators often used in practical communications systems. The present inequalities are satisfied by the results of previous calculations for specific model systems. It is shown that; in contrast to single-channel devices, a two-ended system can act as an amplifier for some input signals and an attenuator for others, even when all the signal frequencies are the same. The output from the two-channel amplifier has a minimum noise determined by the sum of the gains for both input channels, even when only one input channel is used and the other is in its vacuum state. The conditions on device construction needed to achieve equal gains for signals that arrive at the two ends of the device are determined. The present results reduce to those of single-channel theory in special cases where the two output channels are each separately fed by only one of the two input channels.},
doi = {10.1103/PhysRevA.67.033803},
url = {https://www.osti.gov/biblio/20633879}, journal = {Physical Review. A},
issn = {1050-2947},
number = 3,
volume = 67,
place = {United States},
year = {2003},
month = {3}
}