Adiabatic amplification of solitons by means of nonlinear amplifying loop mirrors

Picosecond soliton transmission by use of concatenated gain-distributed nonlinear amplifying fiber loop mirrors

Stable picosecond soliton transmission is demonstrated numerically by use of concatenated gain-distributed nonlinear amplifying fiber loop mirrors (NALMs). We show that, as compared with previous soliton transmission schemes that use conventional NALMs or nonlinear optical loop mirror and amplifier combinations, the present scheme permits a significant increase of loop-mirror (amplifier) spacing. The broad switching window of the present device and the high-quality pulses switched from it provide a reasonable stability range for soliton transmission. We also show that a soliton self-frequency shift can be suppressed by the gain-dispersion effect in the amplifying fiber loop and that soliton-soliton interactions can be partially reduced by using lowly dispersive transmission fibers.

Amplification and compression of ultrashort fundamental solitons in an erbium-doped nonlinear amplifying fiber loop mirror

A nonlinear amplifying loop mirror constructed from erbium-doped fiber is proposed for simultaneous amplification and compression of ultrashort fundamental solitons. Numerical simulations show that, unlike conventional erbium-doped fiber amplifiers in which nonlinear effects lead to serious degradation of pulse quality, the proposed device performs efficient high-quality amplification and compression of ultrashort fundamental solitons while it almost completely preserves the soliton nature of the input pulses. Moreover, the performance of the device is insensitive to small variations in the loop length and in the power-splitting ratio of the coupler.

polarization sensitivity of the nonlinear amplifying loop mirror

A detalled investigation of the coupled dynamlcs of the copropagatlng and counterpropagatlng polarlzation states in the optical loop fiber of a nonlinear amplifying loop mirror is performed Analysis of the dynamlcs yields evidence for the existence of a polarization-insensitive cofiguration of the device.

Nonlinear-optical amplifier based on a dual-core fiber

We propose a scheme for all-optical amplification based on a nonlinear-optical coupler in which one core is amplifying while another is attenuating. In this scheme the input signal is fed into the amplifying core, from where the output is also obtained. A weak input easily couples to the lossy core and gets dissipated in it, whereas a stronger signal stays and undergoes a nearly linear amplification in the active core. When it is used for reshaping pulses in a long transmission line, this scheme should allow the pulses to be amplified while simultaneously suppressing the noises between them. Simulating equations for the cw signal in this model, we are able to find a regime that provides for a strong contrast between the suppression of weak signals and amplification of strong ones as well as a steep transition from suppression to amplification at a certainthreshold.

Spectral filtering of solitons by means of a nonlinear amplifying loop mirror

Soliton evolution in optical fibers and all-optical soliton recovery with a nonlinear active loop mirror have been studied with view to applications in transmission systems having a high bit-rate-]distance product. A 1.3-ps pulse is successfully transmitted over 111 soliton periods, reshaped, amplif ied, and transmitted another 111 soliton periods.