Implications of a zero-nonlinearity wavelength in optical fibers doped   with silver nanoparticles
  Photonic crystal fibers doped with silver nanoparticles exhibit the Kerr nonlinearity that can be positive or negative depending on wavelength and vanishes at a specific wavelength. We study numerically how the simultaneous presence of a zero-nonlinearity wavelength (ZNW) and a zero-dispersion wavelength affects evolution of soliton and supercontinuum generation inside such fibers and find a number of unique features. The existence of negative nonlinearity allows soliton formation even in the normaldispersion region of the fiber, and the ZNW acts as a barrier for the Raman-induced red shift of solitons. 
S. Bose, S. Roy, R. Chattopadhyay, S. K. Bhadra, G.P. Agrawal
physics.optics