63 research outputs found
Bandpass switching in a nonlinear optical loop mirror
A novel device configuration is used to demonstrate wavelength-confined, a bandpass, switching in a nonlinear-optical loop mirror (WOLM). Demonstrated is a self-switching in the soliton regime using a partially reflecting Bragg grating as a wavelength-dependent loss element. Two wavelength operation in which a signal is switched through the use of cross phase modulation, are demonstrated. Observed is the operation of the device confined to wavelengths defined by the grating reflection band
The Gordon-Haus effect for modified NLS solitons
Random jitter in the soliton arrival time (the Gordon-Haus effect) is
analyzed for solitons being solutions of the integrable modified nonlinear
Schroedinger equation. It is shown that the mean square fluctuation of the
soliton position depends on the soliton parameters which can be properly
adjusted to suppress the Gordon-Haus jitter.Comment: LaTeX, 7 pages, 3 figures, to be published in Europhys. Let
Devices and Fibers for Ultrawideband Optical Communications
Wavelength-division multiplexing (WDM) has
historically enabled the increase in the capacity of optical
systems by progressively populating the existing optical bandwidth
of erbium-doped fiber amplifiers (EDFAs) in the C-band.
Nowadays, the number of channels—needed in optical
systems—is approaching the maximum capacity of standard
C-band EDFAs. As a result, the industry worked on novel
approaches, such as the use of multicore fibers, the extension
of the available spectrum of the C-band EDFAs, and the
development of transmission systems covering C- and L-bands
and beyond. In the context of continuous traffic growth,
ultrawideband (UWB) WDM transmission systems appear
as a promising technology to leverage the bandwidth of
already deployed optical fiber infrastructure and sustain the
traffic demand for the years to come. Since the pioneering
demonstrations of UWB transmission a few years ago, long
strides have been taken toward UWB technologies. In this
review article, we discuss how the most recent advances in
the design and fabrication of enabling devices, such as lasers,
amplifiers, optical switches, and modulators, have improved
the performance of UWB systems, paving the way to turn
research demonstrations into future products. In addition,
we also report on the advances in UWB optical fibers, such as
the recently introduced nested antiresonant nodeless fibers
(NANFs), whose future implementations could potentially provide
up to 300-nm-wide bandwidth at less than 0.2 dB/km loss
Multi-band optical systems to enable ultra-high speed transmissions
Current forecasts indicate that the fastest growing IP-traffic is in metro and data center interconnect (DCI) [1]. The exploitation of the entire low-loss spectrum of single-mode fibers (SMF) (from 1260 nm up to 1620 nm) was proposed to avoid the predictable capacity crunch and the eventual need for a new fibre infrastructure roll-out. First analytic result considering multi-band (MB) transmission (from O- to L-band) hint an achievable traffic load exceeding 200 Tb/s for a 500 km link in a single SMF [2]
QoT Evaluation of Optical Line System Transmission with Bismuth-Doped Fiber Amplifiers in the E-Band
We numerically investigate E-band quality of the transmission using an ex-
perimentally characterized bismuth-doped fiber amplifier, demonstrating its impact on
de-ployed C+L system
Soliton switching using cascaded nonlinear-optical loop mirrors
We demonstrate multiple-peaked switching in a nonlinear-optical loop mirror and present an experimental investigation of device cascading in the soliton regime based on a sequence of two independent nonlinear-optical loop mirrors. Cascading leads to an enhanced switching response with sharper switching edges, flattened peaks, and increased interpeak extinction ratios. We observe that pulses emerging from the cascade retain the sech2 temporal profile of a soliton with minimal degradation in the spectral characteristics
Multi-Band Programmable Gain Raman Amplifier
Optical communication systems, operating in C-band, are reaching their theoretically achievable capacity limits. An attractive and economically viable solution to satisfy the future data rate demands is to employ the transmission across the full low-loss spectrum encompassing O, E, S, C, and L band of the single mode fibers (SMF). Utilizing all five bands offers a bandwidth of up to sim53.5 THz (365 nm) with loss below 0.4 dB/km. A key component in realizing multi-band optical communication systems is the optical amplifier. Apart from having an ultra-wide gain profile, the ability of providing arbitrary gain profiles, in a controlled way, will become an essential feature. The latter will allow for signal power spectrum shaping which has a broad range of applications such as the maximization of the achievable information rate × distance product, the elimination of static and lossy gain flattening filters (GFF) enabling a power efficient system design, and the gain equalization of optical frequency combs. In this paper, we experimentally demonstrate a multi-band (S+C+L) programmable gain optical amplifier using only Raman effects and machine learning. The amplifier achieves >1000 programmable gain profiles within the range 3.5 to 30 dB, in an ultra-fast way and a very low maximum error of 1.6 cdot 10{-2} dB/THz over an ultra-wide bandwidth of 17.6-THz (140.7-nm)
86-GBaud subcarrier multiplexed 16QAM signal generation using an electrical 90 degree hybrid and IQ mixers
We experimentally demonstrate an aggregate 86-GBaud (over three sub-bands and one polarization) signal generation based on subcarrier multiplexing technique using IQ mixers, an electrical 90 degree hybrid, and diplexers. The electrical hybrid allows transmitter-side digital signal processing to be simplified to pulse shaping and digital pre-emphasis. We verified the configuration by testing the performance of an 86-GBaud Nyquist-shaped 16 quadrature amplitude modulation signal with differential bit encoding. The implementation penalty assuming 7% hard-decision forward error correction is reduced to 2 dB by utilizing a 31-tap decision-directed least mean square based multiple-input multiple-output equalizer for sideband crosstalk mitigation
Symbolic Toolkit for Chaos Explorations
New computational technique based on the symbolic description utilizing
kneading invariants is used for explorations of parametric chaos in a two
exemplary systems with the Lorenz attractor: a normal model from mathematics,
and a laser model from nonlinear optics. The technique allows for uncovering
the stunning complexity and universality of the patterns discovered in the
bi-parametric scans of the given models and detects their organizing centers --
codimension-two T-points and separating saddles.Comment: International Conference on Theory and Application in Nonlinear
Dynamics (ICAND 2012
Noise and transmission performance improvement of broadband distributed Raman amplifier using bidirectional Raman pumping with dual order co-pumps
We demonstrate a low noise bidirectional broadband distributed Raman pumping scheme combining dual order co-propagated pumps without increasing the signal RIN level. The noise performance improvement is compared experimentally and numerically with conventional counter-pumping only and bidirectional pumping with only a 2nd order co-pump for a 70nm bandwidth and 61.5km distributed Raman amplifier. The proposed broadband pumping scheme shows 1.2dB maximum noise figure improvement and extends the long-haul transmission reach up to 6150km with a Q-factor improvement of ~0.7dB compared with counter-pumping only scheme
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