Title:
OPTICAL AMPLIFIER HAVING AN IMPROVED NOISE FIGURE AND NOISE REDUCTION METHOD
Document Type and Number:
WIPO Patent Application WO2002049243
Kind Code:
A3
Abstract:
A very low noise figure optical amplifier is provided which includes a noise reduction apparatus as part of the structure of the optical amplifier. To improve the signal-to-noise ratio (SNR) of the amplified optical signal, the noise reduction apparatus makes use of the coherence of a coherent component of an amplified optical signal having a coherent signal power and the incoherence of an incoherent component of the amplified optical signal having an incoherent signal power. The amplified optical signal is split in two path signals with each path signal having the same intensity but a different phase. The optical path length the path signals is selected such that coherent path components are combined constructively at a main output while the power of the incoherent path components is divided between the main output and at least one subsidiary output. The result is an increase in the SNR, and a decrease in noise figure (NF) of approximately 3 dB.
Inventors:
LU ZHENGUO (CA)
SO VINCENT (CA)
SO VINCENT (CA)
Application Number:
PCT/CA2001/001774
Publication Date:
January 23, 2003
Filing Date:
December 13, 2001
Export Citation:
Assignee:
BTI PHOTONICS INC (CA)
LU ZHENGUO (CA)
SO VINCENT (CA)
LU ZHENGUO (CA)
SO VINCENT (CA)
International Classes:
H04B10/291; (IPC1-7): H04B10/17
Foreign References:
| GB2320635A | 1998-06-24 | |||
| US5781326A | 1998-07-14 | |||
| EP0901245A1 | 1999-03-10 |
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