Mutual influence of the parametric effects and stimulated Ramanscattering in optical fibers

The effect of Raman gain parametric suppression is investigated both theoretically and experimentally. Good agreement between theory and experiment is obtained. The analysis of the effect of Raman nonlinearity on the process of modulation instability in the region of negative group velocity dispersion of fibers is presented. New dependencies for the modulational instability frequency and increment are calculated     

Efficient compression of high-energy laser pulses

Limitations caused by stimulated Raman scattering (SRS) for laser pulse compression in traditional fiber-grating compressors are discussed. It is shown that the scheme utilizing fibers of length L exceeding the length of the dispersion walk off L_{walk off} of pump pulses and SRS permits one to obtain high-contrast compressed pulses, their energy being no more than a few nJ, and the ultimate width being proportional to the square root of the initial pulse width. For the compression utilizing fibers of length L<L_{walk off}, the pulse energies are not limited, but the compression factor is limited to the value of 32, and the compressed pulses have a low-intensity wide pedestal. A theoretical model of high-energy pulse compression with simultaneous pedestal suppression by the polarization technique using nonlinear birefringence of the fiber is discussed. This technique is compared to the spectral windowing technique     

Massive wavelength-division multiplexing with solitons

Solitons have already enabled the demonstration of many-channel wavelength-division multiplexing (WDM), error free over transoceanic distances, at per-channel rates of 10 and 20 Gbit/s. In this paper, we assess the potential for extending the total transmission rate to many hundreds of gigabit/s in such massive WDM with solitons. We examine the new “dispersion-managed” solitons, as well as the conventional ones, and we consider the advantages of combining each with sliding-frequency guiding filters. Finally, we also describe a practical way for making the required accurate dispersion maps     

New Field Trial Distance Record of 3040 km on Wide Reach WDM With 10 and 40 Gb/s Transmission Including OC-768 Traffic Without Regeneration

Verizon successfully carried Juniper OC-768 traffic on its Richardson, TX, field trial network to 3040 and 2560 km, respectively, using Mintera's 40-Gb/s RZ-DPSK and CS-RZ transponders over Xtera's all Raman Ultra Long Haul system loaded with 68 times 10 Gb/s channels     

Steerable optical waveguides formed by bright spatial solitons inAlGaAs

The authors show theoretically and experimentally that the propagation direction of bright spatial solitons can be easily controlled by spatially varying the phase across the soliton at its input into the nonlinear medium, in this case an AlGaAs slab waveguide. The advantages of bright solitons over dark solitons for steerable waveguides are discussed     

Efficient time-domain demultiplexing with separate signal andcontrol wavelengths in an AlGaAs nonlinear directional coupler

Efficient time-division demultiplexing using two different wavelengths, one for the signal and one for the control beam, has been implemented in an AlGaAs nonlinear directional coupler at 1550 nm. This all-optical demultiplexer makes use of cross-phase modulation and walk-off between the two wavelengths to give high contrast at both low and high powers and to eliminate the pulse break-up. Additionally, ultrafast wavelength shifting has been observed     

DWDM 40G transmission over trans-pacific distance (10 000 km) using CSRZ-DPSK, enhanced FEC, and all-Raman-amplified 100-km UltraWave fiber spans

We demonstrate error-free dense-wavelength-division multiplexing (DWDM) transmission of 40 40-Gb/s channels with 100-GHz spacing over 10 000 km dispersion-managed fiber using carrier-suppressed return-to-zero differential-phase-shift keying (CSRZ-DPSK), enhanced foward-error correction, and all-Raman-amplified spans with 100-km terrestrial length.     

A single-mode fiber with chromatic dispersion varying along thelength

A method for fabrication of a novel type of optical fiber with dispersion varying along the fiber length is described. The method takes into account the calculated dependence of fiber dispersion on fiber core diameter for the measured profile of the preform and the desirable dispersion dependence on the fiber length. The main optical parameters of the drawn fiber are theoretically studied and experimentally measured. The fibers are of great interest for nonlinear fiber optics. Such applications of the fibers, such as high-quality soliton pulse compression, soliton pulsewidth stabilization through compensation of losses, and generation of a high-repetition-rate train of practically uninteracting solitons, are considered     

Generation of fundamental soliton trains for high-bit-rate opticalfiber communication lines

The authors present a method for the generation of high-quality soliton trains at a high repetition rate of gigahertz to terahertz range. During nonlinear propagation of a continuous-wave (CW) dual-frequency signal through a fiber with effective amplification, a train of practically noninteracting fundamental solitons is formed. It is shown that the effective amplification can be achieved as in usual fibers with an actual amplification as well as in fibers with nonuniform parameters along the fiber axis. The method is demonstrated experimentally. Dual-frequency 25 ps pulses at λ=1.55 μm are reshaped into 0.2 THz combs of 0.49 ps solitons in fiber with slowly decreasing dispersion. It is also shown that stimulated Brillouin scattering (SBS) can prevent a CW soliton train transmission through optical fibers, and suggests a method for suppression of SBS