New dispersion decreasing fiber with high SBS threshold for nonlinear signal processing

Abstract

A new &spersion decreasing fiber with reduced SBS by changing the core refiactive index was designed and fabricated. SBS threshold improvement of 7d3 over the conventional

Phosphosilicate Raman gain fibers with varying core concentration for enhanced SBS suppression

“…In this paper we present for the first time the development of new phosphosilicate Raman gain fibers with relatively low attenuation and longitudinally varying core doping concentration levels exceeding 9 mol% over lengths on the order of hundreds of meters that provide for both high Raman gain and enhanced SBS suppression, offering the potential for watt-level amplification of narrow linewidth seed sources across most of the near-infrared spectral band. These fibers stand in contrast to previous efforts in germanosilicate which either resulted in high loss short fibers [4], prohibitive to Raman amplification, or fibers with lengths in excess of several kilometers which significantly decrease the Brillouin threshold under high-power amplification [5][6].…”

40 GHz adiabatic soliton compression of a Mach-Zehnder modulator output in a dispersion decreasing fiber with high SBS threshold

“…To solve this problem, we recently developed a new type of DDF with reduced SBS (RSBS-DDF), where decrease in local dispersion value is achieved by changing the refractive index of the fiber core along its length. The SBS threshold increase of ~7 dB over the conventional nonlinear fiber was demonstrated [6]. In this paper, we demonstrate adiabatic soliton pulse compression at 40 GHz repetition rate in a 5.45 km long RSBS-DDF without using any additional SBS suppression technique.…”

Phase-sensitive amplification in dispersion oscillating fibers

“…Variation of fiber disperspersion can be used for suppression of SBS in the process of parametric amplification. In dispersion decreasing fibers [15] or strained fibers [16] change of the effective refractive index distort the phase matching condition for FWM that, in turn, reduce bandwidth of parametric gain. DOF has some advantages for SBS suppression with FWM parametric gain because the sinusoidal oscillation of the fiber dispersion does not affect the fundamental gain spectrum (q = 0).…”

“…The concept of dispersion modulation may be useful for suppression of SBS. SBS can be suppressed in dispersion decreasing fibers [15], strained fibers [16] and fibers with temperature gradient [17]. Change of the effective refractive index along the fiber reduces power transfer from the pump wave to the back propagating Stokes wave.…”