Optical amplifiers have made a great achievement and huge revolution in the world of optical communications, but some shortcomings must be occurs, for example, backward pump Raman amplifier suffers from decrease gain. The main objective this paper is to solve problem that occurs gain pumped amplifier. To problem, we design model two are used cascaded form overcome attenuation We present results...

We propose and demonstrate the use of narrow band optical parametric amplification for tunable slow and fast light propagation in optical fibers. The parametric gain is coupled to the Raman process which changes the gain value moderately but modifies the gain spectral shape. Consequently, the delay is enhanced at short wavelengths while it is moderated at long wavelengths. The maximum delay and...

We develop an analytic model for finding the statistics of polarization-dependent gain (PDG) in fiber-based Raman amplifiers. We use it to find an analytic form for the probability distribution of PDG and study how the mean PDG and the variance of PDG fluctuations depend on the PMD parameter. We show that mean PDG as well as PDG fluctuations are reduced by approximately a factor of 30 in the ca...

We present a new method to generate dark soliton trains by exploiting the interaction between two time-delayed optical similaritons with the same wavelength. The temporal overlap of two similariton pulses creates a sinusoidal beating which subsequently evolves into an ultrahigh repetition-rate train of dark solitons through the combined effects of normal dispersion, non-linearity and adiabatic ...

A 90-nm wideband (1500-1590nm) optical amplifier consisting of a dispersion-compensated-fiber-based Raman fiber amplifier and a semiconductor optical amplifier with gain clamping and dispersion compensation is demonstrated for wide bandwidth amplification with gain flatness as well as dispersion compensation. 10Gb/s DWDM transmission over 100km conventional single-mode fiber link with low biter...