Open AccessPhase sensitive amplification with noise figure below the 3 dB quantum limit using CW pumped PPLN waveguide
Author(s) -
Masaki Asobe,
Takeshi Umeki,
O. Tadanaga
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.013164
Subject(s) - optics , optical amplifier , amplifier , waveguide , preamplifier , materials science , amplified spontaneous emission , lithium niobate , noise figure , quantum limit , phase noise , physics , optoelectronics , laser , quantum , cmos , quantum mechanics
The noise figure (NF) of a phase sensitive amplifier (PSA) based on a periodically poled LiNbO3 (PPLN) waveguide was evaluated in the optical and electrical domains. Phase sensitive amplification was realized using degenerate parametric amplification in the PPLN waveguide, which was pumped by the second harmonic frequency of the signal. Second harmonic pumping enables direct observation of the intrinsic amplified spontaneous emission (ASE), which determined the NF of the PSA. An NF below the 3 dB quantum limit was obtained by observing the intrinsic ASE. The low NF was also confirmed via the noise floor measurement of a cascaded PSA and erbium doped fiber amplifier in the electrical domain. The PSA was used as a preamplifier for detecting a 40 Gbit/s phase shift keying signal. The low noise characteristics were confirmed by the improved sensitivity.