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Recently, we have demonstrated internal net gain with a bandwidth of 80 nm (1500 - 1580 nm) and 1533 nm peak gain of 2.0 dB/cm in Al2O3:Er3+ channel waveguides which were sputtered on silicon substrates and subsequently reactive ion etched. Based on measured spectroscopic parameters, rate-equation simulations predict gain of >20 dB throughout the entire telecom C-band for optimized waveguide lengths...
Dynamic behavior caused by Brillouin scattering in Raman fiber amplifiers is studied. Modes of self-pulsation steady state oscillations are found. Their dependence on amplification scheme is demonstrated.
Noise performance of parametric amplifiers is typically calculated assuming un-depleted operation. However, in many applications especially when applied as regenerative amplifiers in systems based on phase shift keyed modulation schemes, this assumption is not valid. Here we show the impact on accumulated spontaneous emission for a parametric amplifier operated in saturation.
Parabolic pulses in optical fibers have stimulated an increasing number of applications. We review here the physics underlying the generation of such self-similar pulses as well as the results obtained in a wide-range of passive or active experimental configurations.
In transparent WDM networks, the optical signal crosses several equipments (cross-connect, amplifiers and subfibers) and while the signal is propagated, the optical components causes their degradation. Thus, paths with low signal quality should be avoided, especially when the application requires quality of service (QoS). In this context, an appropriate allocation of resources requires encompassing...
This paper presents a wavelength assignment algorithm for all optical networks. The main idea is to determine the wavelength assignment order for a first fit algorithm taking into account the physical layer effects, such as four wave mixing and residual dispersion, by using a training algorithm inspired in evolutionary computation concepts. The intelligent algorithm uses an external archive to store...
The aim of this paper is to present the activity related to the development of fiber laser systems for the scribing of photovoltaic modules realized by using two of the most appealing solar cell technologies, that is CdTe and CIS or CIGS based thin films. The activity is carried out by the EU funded ALPINE - Advanced Lasers for Photovoltaic INdustrial processing Enhancement - project. The consortium...
The use of semiconductor optical amplifiers (SOA) in optical communications networks has so far been limited due to their inherent large noise figure (NF) compared to Erbium Doped Fibre Amplifiers. Therefore improvement of the noise performance of SOAs is critical to their widespread adoption in future networks. We propose to reduce the NF of the SOA by introducing a lasing cavity lateral to the axis...
A new method of phase modulation to amplitude modulation conversion (PM/AM conversion) based on an integrating capabilities of uniform fiber Bragg grating (FBG) was proposed and its use in a wavelength converter was experimentally demonstrated. The wavelength converter was based on cross-phase modulation XPM in 500 m of highly nonlinear fiber. The pulsewidth of input pulses was 1.5 ps and the pulsewidth...
In this paper, we report recent progress on the design of all-fibered ultra-high repetition-rate pulse sources for telecommunication applications around 1550 nm. Based on the nonlinear compression of an initial beat-signal in optical fibers through a multiple four-wave mixing process, we theoretically and experimentally demonstrate that this simple technique allows an efficient and accurate design...
In this work we investigate the coating damages in optical fibers under the simultaneous effects of high optical power and tight bending. The power losses and coating heating imposed by the high power propagation have been measured for a SMF fiber. We have implemented a theoretical thermal model for the fiber bend and the minimum safety bend diameter has been established.
In this paper, we analyze bidirectional Downstream and Upstream amplification for gain transient mitigation in Remote Erbium Doped Fibre Amplifiers. Amplifying a Continuous Downstream and a burst mode Upstream data traffic in the same remotely pumped Erbium Doped Fibre Amplifier, a reduction of the overshoot and BER penalty have been experimentally measured for different packet lengths. In addition,...
In this paper, a study on a fully passive WDM/PON ring architecture which reaches 19 km distance, while serving more than 1000 users with symmetric several hundred Mbit/s per user is presented. The design is based on SARDANA (Scalable Advanced Ring -based Passive Dense Access Network Architecture) and was generated as an alternative solution, with its novelty laying on the use of L-band in line remote...
In this paper, we describe compact laser sources based on high-power amplification in Yb-doped silica fibers of ultra-stable mode-locked pulses from an all-fiber oscillator. The interplay between third-order nonlinearity, gain and chromatic dispersion in the polarization-maintaining fiber amplifier is engineered to produce high-quality, high-energy pulses suitable for nonlinear generation of light...
A numerical method to generate frequency-shaped noise is proposed. Using this method, a model describing the optical noise originated by Raman amplification in optical fibers is presented. The numerical simulations for the amplified spontaneous emission noise power spectrum were corroborated with experimental results.
Raman Fiber Amplifiers (RFA) are assuredly one of the most seriously renewed research subjects in the field of optical fiber communication systems. The amplification is based on stimulated Raman scattering (SRS), which occurs when there is enough pumping power within the fiber transferred to the signals. In the simplest situation, only the interaction between the pumping lasers and the probe signals...
Experimental results obtained on 10 Gb/s RZ-DPSK transmission in a recirculating fiber-loop setup have shown that nonlinear amplifying loop mirrors (NALM) can efficiently enhance system performance: cascaded phase-preserving amplitude regeneration can efficiently prevent the accumulation of amplitude and nonlinear phase noise components in such systems. It was possible to significantly augment the...
We present a leaky thulium-doped photonic crystal fibre (PCF) design to down shift the thulium emission in the 1.7 - 1.8 mum band. The microstructured cladding structure manages confinement loss to counteract the thulium emission cross section. Thus, the fibre is considered as a distributed low pass filter along the fibre length. Computations on confinement loss show differential loss two orders of...
We present experimental and theoretical results showing the emergence of rogue wave-like extreme intensity spikes during fiber-based amplification processes such as Raman effect or induced-modulational instability that rely on quasi-instantaneous gain. We outline that under certain circumstances, a partially incoherent pumping can induce large fluctuations of the amplified signal, and we propose various...
We investigate the nonlinear propagation of ultra-short pulses in multimode optical fibers. At high peak powers, close to the critical power for self-focusing in bulk materials, a four-wave mixing process is observed which transfers power from the fundamental fiber mode to higher-order modes and leads to transverse spatial pulse compression. The interplay of this spatial effect with the temporal dynamics...
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