S. Radic

Parametric amplifiers driven by two pump waves

Parametric amplifiers (PAs) are well-suited for optical communication systems. Not only can PAs provide high gain for arbitrary signal wavelengths, they can also conjugate the signals and convert their wavelengths. The four-sideband model of parametric amplifiers driven by two pump waves will be reviewed and used to describe the conditions required to produce broad-bandwidth gain. The flexibility of the two-pump architecture allows it to produce gain that is nearly independent of the signal polarization, and idlers whose spectral widths are comparable to that of the signal.

All-optical regeneration in one- and two-pump parametric amplifiers using highly nonlinear optical fiber

We describe the operation of a two-pump parametric optical regenerator. It is shown that higher order parametric coupling provides optical regeneration with a high extinction ratio. Excessive spectral broadening is studied in a two-pump architecture and compared with that of the one-pump parametric regenerator. We show that the spectral widths of the higher order terms can be controlled in amplifiers by using counterphased optical pumps.

Continuous-wave parametric gain synthesis using nondegenerate pump four-wave mixing

The authors demonstrate continuous-wave parametric amplification using modulational interaction between two spectrally distant optical pumps and a single section of uniform fiber. The proposed configuration is used to synthesize flat parametric gain over more than 22-nm bandwidth.

Selective suppression of idler spectral broadening in two-pump parametric architectures

We describe methods for selective suppression of idler spectral broadening in two-pump fiber parametric fiber amplifiers. Combinations of multiple amplification bands and dissimilar pump modulation techniques are used to generate narrow idlers at preselected wavelengths. In-phase pump modulation is shown to eliminate the need for phase-delay management in two-pump parametric amplification schemes.

Dual-order Raman pump

This letter presents the design of a dual-order Raman fiber laser to be used as a pump for distributed Raman amplification. In particular, noise figure, gain ripple, and tunability are measured and analyzed in comparison to first-order Raman amplification. The tradeoff between noise figure improvement and increased nonlinear penalty is also discussed.

Wavelength division multiplexed transmission over standard single mode fiber using polarization insensitive signal conjugation in highly nonlinear optical fiber

We demonstrate 10 Gb/s, 5-channel, wavelength multiplexed transmission over four 80-km standard fiber spans using polarization invariant spectral inversion provided by a broadband fiber parametric amplifier using orthogonally-polarized pumps having synchronized phase modulation for stimulated Brillouin suppression.

Multiple-band bit-level switching in two-pump fiber parametric devices

We investigated the feasibility of multiple-band switching using a two-pump fiber parametric device. The switching architecture combines band amplification, wavelength conversion, and selective signal conjugation, enabled by temporal control of one or both parametric pumps. A switching scheme with a single pump control was constructed and evaluated. Multiple-band bit-level optical switching is demonstrated over bandwidth greater than 50 nm, with a maximal conversion efficiency of 24.2 dB.

Limitations in dense bidirectional transmission in absence of optical amplification

We investigate impairments induced by Rayleigh backscattering in the case of very dense bidirectional optical transmission. It is found that the severe penalty for the worst case scenario of spectrally overlapping counterpropagating channels can be mitigated by controlling channel polarization states.

Forward error correction performance in the presence of Rayleigh-dominated transmission noise

The performance of a forward error correction scheme is investigated in the presence of Rayleigh induced optical noise. The signal coherence and relative polarization states of the signal and Rayleigh backscatter are found to influence strongly the performance of the transmission architecture.

1.6-Tb/s (160 x 10.7 Gb/s) transmission over 4000 km of nonzero dispersion fiber at 25-GHz channel spacing

We report transmission of 1.6 Tb/s (160/spl times/10.7 Gb/s) over 4000 km of nonzero dispersion fiber at 25-GHz channel spacing using 100-km amplified spans. Without polarization interleaving and per-channel post dispersion compensation, all channels have better than 1/spl times/10/sup -4/ bit-error rate, corresponding to error-free performance with forward-error-correction. We present experimental investigation on the transmission impairments and identify potential approaches for performance improvement.