"Superluminal" Propagation Of Optical Pulse In Photonic Crystal Fibers

In order to meet the increasing requirement of the future optical communication, All-optical network is the future development direction of optical communication. However, large capacity and high speed of all-optical network communications require high efficiency of optical signal processing. The improvement of its efficiency depends on the development of all-optical buffer, optical switch and photoelectric transducer all-optical communication devices, and the all-optical buffer depends on the slow and fast light technology. Because fast or slow light based on optical fiber stimulated Brillouin scattering has many advantages For example, operating at room temperature, continuously adjusted wavelength, good compatibility. So fast light and slow light become a hot research spot.First, the theory model of stimulated Brillouin scattering is set up in this paper. Jung Curta Fa and characteristic line method were used to numerically simulate and solve the three coupled wave equations. The influence of simple pump stimulated Brillouin scattering characteristic parameters, such as pulse half peak full width(FWHM), optical signal power and fiber length on the fast light of Gauss pulse is investigated in photonic crystal fibers. For the influence of different broadband pump on signal waveform distortion, We also studied the influence of rectangular and Gaussian shaped broadband pump on stimulated Brillouin scattering fast light for different signal waveform.The main contents and achievements are as follows.1. The time advancement increases along with the increase of input pump power, and increases with the increase of Brillouin absorption, overall pulse broadening factor decreases with the increase of the input pump power and the Brillouin absorption(other). Analyzing the influence of fiber length on the SBS fast optical transmission, we know signal pulse’s time advancement increase slowly at first as the optical fiber length increases, and finally tends to saturation, it almost don’t increase with the increase of fiber length, besides the signal light pulse broadening factor is first increased then decreased with the increase of fiber length. Considering the signal pulse width’s influence on fast light, the advancement of signal decreases after increasing first with the increase of input pulse width, and the pulse broadening factor is as well. When considering the input signal power, under the condition of different input pump power, signal’s time advancement is increased slowly and then tend to be saturated as the increase of input signal power, with the increase of input signal light peak power, pulse broadening factor decreases and tends to saturation at last.2. Regardless of the rectangular broadband pump or Gaussian broadband pump, signal’s time advancement decreases and tends to saturation with the increase of input pump bandwidth, but pulse broadening factor increases with the increase of input pump bandwidth and the pulse width distortion is getting smaller and smaller. The rectangular broadband pump is more able to reduce the signal pulse distortion than the Gauss broadband pump.3. For the same waveform and bandwidth of input broadband pump, Gaussian signal has much larger time advancement and pulse broadening factor than the hyperbolic secant and Lorentz signals, at the same time pulse distortion is smaller too.