An experimental investigation of the temperature dependence of the gain and noise performance of a silica-fiber Raman amplifier is described. A decrease in the Raman scattering cross section in a fiber amplifier cooled from a temperature of 300 K to 77 K was measured and found to be in agreement with theoretical values. No difference between the Raman gain coefficients at these two temperatures...

Due to the benefits of Raman amplifier for Long-Haul UW-WDM Optical Communications Systems, we interest in this paper to investigate the parameters affecting on Raman gain and bandwidth, and also we are analyzed four and eight Raman pumping of special pump power and pumping wavelengths to show the effect of this parameters on gain and bandwidth. The model equations are numerically handled and p...

We present a technique to measure the tensor components of the Raman gain spectrum in a short piece of optical fiber. Using this approach, we obtain results for the frequency dependence of the Raman gain tensor in a silica-based fiber for Raman shifts from less than 1 to over 15 THz. We compare these data with measurements of spontaneous Raman scattering in bulk silica and find good agreement f...

Abstract The backward Raman amplifier (RA) can considered as one of the best solutions for optical communication, especially in Wavelength Division Multiplexing technology. They reduce nonlinear effects, have low noise figure and a wide frequency range. work this paper aims to attenuation signal due its propagation fiber increase both gain output power. Two models are proposed. Proposal model c...

We have measured the vibrational Raman spectrum of a 1.2-microm-thick polystyrene film by using this film as an optical waveguide in a waveguide-stimulated Raman gain experiment. A gain factor of 1.3% was measured for the strong benzene mode at 1002 cm(-1). This value is in reasonable agreement with theoretical predictions.

Amplification of ultrashort solitons in fiber amplifiers is discussed by considering a general model that includes gain saturation, gain dispersion, and intrapulse stimulated Raman scattering. The numerical results show that an interplay between gain dispersion and intrapulse Raman scattering can lead to novel temporal and spectral features. Under high-gain conditions the input pulse is found t...

Raman amplifiers are widely used for high capacity long haul communication systems. One of the main reason for which it can be used as its improved gain. In this paper gain of Raman amplifiers is studied and analyzed for counter pumping scheme. The methods to improve the gain is proposed and discussed. The previous result is being compared with the model proposed in this paper.

Introduction Scattering of optical radiation by materials is a topic that has received much attention over the past 100 years. One particular type, Raman scattering, was first observed by C.V. Raman in 1928, and since then this inelastic scattering process has found many uses in basic and applied science. Raman scattering can be used to make spectroscopic measurements, or exploited to build Ram...