60 research outputs found
Optical gap solitons and truncated nonlinear Bloch waves in temporal lattices
We experimentally demonstrate the formation and stable propagation of various
types of discrete temporal solitons in an optical fiber system. Pulses
interacting with a time-periodic potential and defocusing nonlinearity are
shown to form gap solitons and nonlinear truncated Bloch waves. Multi-pulse
solitons with defects, as well as novel structures composed of a strong soliton
riding on a weaker truncated nonlinear Bloch wave are shown to propagate over
up to eleven coupling lengths. The nonlinear dynamics of all pulse structures
is monitored over the full propagation distance which provides detailed insight
into the soliton dynamics.Comment: accepted in Phys. Rev. Let
Experimental observation of spectral Bloch oscillations
We report on the first, to our knowledge, experimental observation of spectral Bloch oscillations in an optical fiber employing the interaction between a probe signal and a traveling-wave periodic potential. The spectrum of weak probe pulses is shown to oscillate on account of their group-velocity mismatch to the periodic field. The behavior of a cw probe spectrum reveals the actual discrete nature of the effect. Recurrences of the spectrum after one and two Bloch periods are demonstrated. (C) 2009 Optical Society of Americ
Spectral and temporal Bloch oscillations in optical fibres
Inspired by the space-time duality of paraxial beam diffraction and dispersive pulse spreading, the experimental implementation of a temporal equivalent of evanescently coupled waveguide arrays is demonstrated. Pulses interact with a time-periodic potential during their propagation through an optical fibre and the generic effect of discrete diffraction is observed in time. The presented system allows fast and high-resolving measurements of the complete signal evolution. To demonstrate the advanced capabilities, Bloch oscillations of an optical signal in both the time and frequency domains are realised
Experimental observation of spectral Bloch oscillations
We report on the first, to our knowledge, experimental observation of spectral Bloch oscillations in an optical fiber employing the interaction between a probe signal and a traveling-wave periodic potential. The spectrum of weak probe pulses is shown to oscillate on account of their group-velocity mismatch to the periodic field. The behavior of a cw probe spectrum reveals the actual discrete nature of the effect. Recurrences of the spectrum after one and two Bloch periods are demonstrated. (C) 2009 Optical Society of Americ
Experimental Observation of Bloch Oscillations in the Spectral Domain
We have experimentally demonstrated for the first time spectral Bloch oscillations using the interaction between a probe signal and a traveling-wave periodic potential in an optical fiber
Discreteness in time
In this paper we discuss the joint propagation of a periodically modulated field and a pulse of different frequency in an optical fiber. The pulse experiences the action of an index lattice induced via cross-phase modulation by the periodic field. We predict effects of discreteness to show up both in the temporal and in the spatial domain. For large walk-off between the two fields one should observe Bloch oscillations in frequency space, where discrete diffraction is expected to occur for equal velocities of both waves
Effect of Group-Velocity Dispersion in Multilevel Amplitude Regenerator based on a Nonlinear Amplifying Loop Mirror
Non-zero fiber dispersion in a Sagnac interferometer can significantly improve multilevel phase-preserving amplitude regeneration. Soliton effects can be used to create irregularly spaced plateaus for high-power states of complex modulation formats. (C) 2012 Optical Society of Americ
Multilevel Amplitude and Phase Regeneration in a Nonlinear Amplifying Loop Mirror with a Phase-Sensitive Amplifier
A novel regenerator scheme for all-optical multilevel simultaneous amplitude and phase noise suppression is proposed. For a star-8QAM signal, consisting of two amplitude and four phase states, EVM reduction is 4 dB and 2.5 dB for the high- and low-power states, respectively. The limiting effects of the regenerator performance have been considered
Cascaded phase-preserving multilevel amplitude regeneration
The performance of cascaded in-line phase-preserving amplitude regeneration using nonlinear amplifying loop mirrors has been studied in numerical simulations. As an example of a spectrally efficient modulation format with two amplitude states and multiple phase states, the regeneration performance of a star-16QAM format, basically an 8PSK format with two amplitude levels, was evaluated. An increased robustness against amplified spontaneous emission and nonlinear phase noise was observed resulting in a significantly increased transmission distance. (C) 2014 Optical Society of Americ
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