0000000000072789
AUTHOR
David J. Richardson
PSA-based phase regeneration of DPSK signals in a silicon germanium waveguide
We demonstrate a polarization-assisted PSA-based phase regenerator in a passive low-birefringence SiGe waveguide at low CW pump power. A PSER of 28.6-dB enables a six-fold reduction in phase-error and BER improvement of approximately 2-dB in the regenerated signal.
Parabolic pulse generation and applications
Parabolic pulses in optical fibers have stimulated an increasing number of applications. We review here the physics underlying the generation of such pulses as well as the results obtained in a wide-range of experimental configurations.
Telecom to mid-infrared supercontinuum generation in a silicon germanium waveguide
We report the first demonstration of broadband supercontinuum generation in silicon-germanium waveguides. Upon propagation of ultra-short femtosecond pulses in a 3-cm-long waveguide, the broadening extended from 1.455µm to 2.788µm (at the −30-dB point).
Generation of localized pulses from incoherent wave in optical fiber lines made of concatenated Mamyshev regenerators
International audience; We investigate the novel properties of optical fiber lines made of Mamyshev regenerators (MRs) based on self-phase modulation and subsequent spectral filtering. In particular, we show that such a regenerator line can be used to generate random sequences of optical pulses from an incoherent wave. This behavior is related to the existence of stable eigenpulses that can propagate unchanged through the regenerator line and act as attractors for incoming pulses. By changing the regenerator parameters, we also report the existence of multiple eigenpulses and limit cycles. Finally, we demonstrate that MRs could be used as efficient nonlinear gates in fiber laser cavities.
Generation of parabolic pulses and applications for optical telecommunications
International audience; 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.
Record Phase Sensitive Extinction Ratio in a Silicon Germanium Waveguide
A binary step-like phase response and phase-sensitive extinction ratio in excess of 28dB under CW pump operation was demonstrated in a 20mm-long low birefringence SiGe waveguide, using a polarization-assisted phase sensitive amplifier scheme.
Parabolic pulse generation through passive reshaping of gaussian pulses in a normally dispersive fiber
We numerically and experimentally demonstrate that a Gaussian pulse can be reshaped into a pulse with a stable parabolic intensity profile during propagation in normally dispersive nonlinear fibers.
High speed optical transmission at 2 μm in subwavelength waveguides made of various materials
We report the transmission of a 10 Gbps telecommunication signal at 2 μm in waveguides made of three different materials: Si, SiGe and TiO2. Bit error rates below 10−9 can be achieved after transmission in the devices with subwavelength dimensions.
Simultaneous 2R regeneration of WDM signals in a single optical fibre
Two experimental implementations of amplitude regeneration of WDM signals based on self-phase modulation (SPM) in optical fibres are discussed. The two examples differ in their approach of mitigation of inter-channel nonlinearities.
Data Transmissions at 1.98 µm in cm-long SiGe Waveguides
International audience; We demonstrate an error-free transmission of 10-Gbit/s optical signals along a SiGe waveguide at a wavelength of 1.98 μm. Bit error rate measurements confirm the absence of penalty during the transmission through a 2.5-cm long waveguide having a width of 2.2 μm.
Parabolic pulse evolution in normally dispersive fiber amplifiers preceding the similariton formation regime
We show analytically and numerically that parabolic pulses and similaritons are not always synonyms and that a self-phase modulation amplification regime can precede the self-similar evolution. The properties of the recompressed pulses after SPM amplification are investigated. We also demonstrate that negatively chirped parabolic pulses can exhibit a spectral recompression during amplification leading to high-power chirp-free parabolic pulses at the amplifier output.
2R regeneration architectures based on multi-segmented fibres
The benefits of using a multi-segmented arrangement of optical fibres for Self-Phase Modulation-based 2R optical regeneration are described both theoretically and experimentally. Significant improvements in terms of the performance and practicality are achieved.
Generalisation and experimental validation of design rules for self-phase modulation-based 2R regenerators
We report the design of 2R-regenerators based on self-phase modulation in lossy fibers. We experimentally demonstrate the applicability of the proposed scaling rules and present detailed characterization of the pulse characteristics at the regenerator output.
Ultra-flat SPM-broadened spectra in a highly nonlinear fiber using parabolic pulses formed in a fiber Bragg grating
International audience; We propose a new method for generating flat self-phase modulation (SPM)-broadened spectra based on seeding a highly nonlinear fiber (HNLF) with chirp-free parabolic pulses generated using linear pulse shaping in a superstructured fiber Bragg grating (SSFBG). We show that the use of grating reshaped parabolic pulses allows substantially better performance in terms of the extent of SPM-based spectral broadening and flatness relative to conventional hyperbolic secant (sech) pulses. We demonstrate both numerically and experimentally the generation of SPMbroadened pulses centred at 1542nm with 92% of the pulse energy remaining within the 29nm 3dB spectral bandwidth. Appli…
Self-similarity in ultrafast nonlinear optics
International audience; Recent developments in nonlinear optics have led to the discovery of a new class of ultrashort pulse, the `optical similariton'. Optical similaritons arise when the interaction of nonlinearity, dispersion and gain in a high-power fibre amplifier causes the shape of an arbitrary input pulse to converge asymptotically to a pulse whose shape is self-similar. In comparison with optical solitons, which rely on a delicate balance of nonlinearity and anomalous dispersion and which can become unstable with increasing intensity, similaritons are more robust at high pulse powers. The simplicity and widespread availability of the components needed to build a self-similar amplif…
Polarization insensitive wavelength conversion of 40 Gb/s DPSK signals in a silicon germanium waveguide
We demonstrate polarization insensitive FWM-based wavelength conversion of 40Gb/s DPSK signals in a SiGe waveguide, with 0.42-dB polarization-dependent loss. A 1.5-dB Dower nenaltv was measured at a BER of 10−9.
Parabolic pulse formation and applications
Parabolic pulses in optical fibers have stimulated an increasing number of applications. We review here the physics underlying the generation of such pulses as well as the results obtained in a wide-range of experimental configurations.
Ultra-flat SPM-broadened spectra in a highly nonlinear fiber using a fiber Bragg grating based parabolic pulse shaper
We demonstrate the generation of ultra-flat broadened spectra by seeding a nonlinear fiber with parabolic pulses shaped using a fiber grating. Applications in pulse compression and spectral slicing are shown.
Broadband telecom to mid-infrared supercontinuum generation in a dispersion-engineered silicon germanium waveguide.
We demonstrate broadband supercontinuum generation (SCG) in a dispersion-engineered silicon-germanium waveguide. The 3 cm long waveguide is pumped by femtosecond pulses at 2.4 μm, and the generated supercontinuum extends from 1.45 to 2.79 μm (at the −30 dB point). The broadening is mainly driven by the generation of a dispersive wave in the 1.5–1.8 μm region and soliton fission. The SCG was modeled numerically, and excellent agreement with the experimental results was obtained.
Design scaling laws for self-phase modulation-based 2R-regenerators
We report global scaling laws linking the design of SPM-based 2R-regenerators to their ability to reduce amplitude noise and improve the signal extinction ratio.
Polarization Insensitive Wavelength Conversion in a Low-Birefringence SiGe Waveguide
We report the first demonstration of a single-pass dual-orthogonal-pump four-wave mixing-based wavelength conversion scheme in a silicon-based waveguide. The silicon germanium waveguide used was designed to exhibit strong TE/TM mode similarity across a broad wavelength range as well as a large nonlinear coefficient. A polarization-dependent loss of just 0.42 dB was measured, and the conversion of 40-Gb/s differential phase-shift keying signals was demonstrated with 1.5-dB power penalty at a bit error ratio of $10^{-9}$ .