Slow-Nonlinearity Assisted Supercontinuum Generation in a CS₂-Core Photonic Crystal Fiber

In this paper, we theoretically investigate the supercontinuum generations (SCGs) in a carbon disulfide (CS₂)-core photonic crystal fiber (PCF). We show that the intrinsic slow nonlinearity of CS₂ plays a significant role to control the soliton fission process. The initiation of the soliton fission process can be distinctly delayed. More importantly, the transition between the smooth soliton fission and the sub-solitons' chaotic-like interference is sufficiently extended so that the optical spectrum can keep broadening continuously while still maintaining a smooth spectral profile. When pumping a designed CS₂-core PCF at wavelength 1.55 μ m in the anomalous dispersion region, we obtain temperature-controllable and highly coherent SCs spanning over one octave at the-30-dB spectral intensity. The unique feature of large slow nonlinearity and the controllable dispersion and nonlinearity of CS₂-core PCF confirm that as a versatile platform for highly coherent and octave-spanning SCGs.