ABSTRACT
The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time-division multiplexed formats. High-quality mid-span spectral inversion has been demonstrated at 0.64 Tb/s, avoiding electronic dispersion compensation. All-optical amplitude regeneration of amplitude-modulated signals has been performed, while PSAs have been used to demonstrate phase regeneration of phase-modulated signals. A PSA with 1.1-dB noise figure has been demonstrated, and preliminary wavelength-division multiplexing experiments have been performed with PSAs. 512 Gb/s have been transmitted over 6,000 km by periodic phase conjugation. Simulations indicate that PIAs could reach data rate x reach products in excess of 14,000 Tb/s × km in realistic wavelength-division multiplexed long-haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long-haul communication networks are discussed. [Formula: see text].
ABSTRACT
One of the most remarkable and useful properties of a spatially converging lens system is its inherent ability to perform the Fourier transform; the same applies for the time-lens system. At the back focal plane of the time-lens, the spectral information can be instantaneously obtained in the time axis. By implementing temporal Fourier transform for spectroscopy applications, this time-lens-based architecture can provide orders of magnitude improvement over the state-of-art spatial-dispersion-based spectroscopy in terms of the frame rate. On the other hand, in addition to the single-lens structure, the multi-lens structures (e.g. telescope or wide-angle scope) will provide very versatile operating conditions. Leveraging the merit of instantaneous response, as well as the flexible lens structure, here we present a 100-MHz frame rate spectroscopy system - the parametric spectro-temporal analyzer (PASTA), which achieves 17 times zoom in/out ratio for different observation ranges.
ABSTRACT
We experimentally demonstrate amplification of 1.28 Tb/s DWDM channels using a bidirectional fiber optical parametric amplifier. The amplifier can provide more than 13 dB on-off gain on all 32 DWDM channels. Error-free operation has been achieved for all data streams, with an average power penalty of 2.5 dB compared with conventional unidirectional configuration.
ABSTRACT
Following a fiber optical parametric amplifier, used as a wavelength converter or in the phase-sensitive mode, by a phase-insensitive amplifier (PIA) can significantly reduce four-wave mixing between signals in broadband systems. We derive the quantum mechanical noise figures (NF) for these two hybrid configurations, and show that adding the PIA only leads to a moderate increase in NF.
Subject(s)
Amplifiers, Electronic , Lasers , Telecommunications/instrumentation , Equipment Design , Equipment Failure Analysis , Signal-To-Noise RatioABSTRACT
By using the four-sideband theory, we analyze the gain spectrum in wideband two-pump fiber optical parametric amplifiers and predict gain ripples over the flat gain region. We derive an approximation of their pseudo-periods and discuss methods for reducing their amplitudes.
ABSTRACT
We demonstrate the advantages of an optically gain-clamped S-band discrete Raman amplifier: low gain variation over a large input dynamic range, effective suppression of Raman transients, and amplifier instability in the strong-pump-weak-signal configuration. We further investigate experimentally the operating conditions necessary for effective gain clamping and demonstrate gain flattening over 30 nm of bandwidth. Thus a gain-clamped discrete Raman amplifier shows promise for practical deployment.
ABSTRACT
An improved full-vectorial method exploiting the opposite-parity property of eigenmodes based on orthonormal-functions expansion is proposed to solve the wave equation for holey optical fibers. By use of the parity property of eigenmodes in symmetric structures, the number of orthonormal function integrals involved in the calculation is reduced, and the computation efficiency is greatly enhanced. The coupling between the two transverse field components is considered, and both dominant and minor field components can be calculated for the accurate modeling of fiber modes. This method is useful for efficiently modeling holey fibers, especially those with large air holes, in which the coupling effect that is due to refractive-index discontinuities is strong.
ABSTRACT
We have obtained 40 dB of internal (on-off) conversion gain and a sub-4-dB noise figure (NF) with a continuous-wave (cw) fiber optical parametric wavelength converter. To our knowledge, this is the lowest NF reported for any cw wavelength converter. We have also investigated the properties of NF versus signal input power and pump power.
