Excess noise in gain-guided amplifiers
- Department of Physics, University of California, Berkeley, California 94720 (USA)
- Lawrence Livermore National Laboratory, University of California, Livermore, California 94550 (USA)
- Optical Sciences Center, University of Arizona, Tucson, Arizona 85721 (USA)
A second-quantized theory of the radiation field is used to study the origin of the excess noise observed in gain-guided amplifiers. We find that the reduction of the signal-to-noise ratio is a function of the length of the amplifier, and thus the enhancement of the noise is a propagation effect arising from longitudinally inhomogeneous gain of the noise rather than from an excess of local spontaneous emission. We confirm this conclusion by showing that the microscopic rate of spontaneous emission into a given non-power-orthogonal cavity mode is not enhanced by the Petermann factor. In addition, we illustrate the difficulties associated with photon statistics for this and other open systems by showing that no acceptable family of photon-number operators corresponds to a set of non-power-orthogonal cavity modes.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5552799
- Journal Information:
- Journal of the Optical Society of America, Part B: Optical Physics; (USA), Vol. 8:6; ISSN 0740-3224
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AMPLIFIERS
NOISE
OPTICAL SYSTEMS
GAIN
LANGEVIN EQUATION
PHOTONS
QUANTUM FIELD THEORY
STATISTICS
WAVE PROPAGATION
AMPLIFICATION
BOSONS
ELECTRONIC EQUIPMENT
ELEMENTARY PARTICLES
EQUATIONS
EQUIPMENT
FIELD THEORIES
MASSLESS PARTICLES
MATHEMATICS
426002* - Engineering- Lasers & Masers- (1990-)