Nonlinear chalcogenide fiber

Chalcogenide fibers used in our experiments are formed from very high purity materials in order to achieve single mode fibers with relatively low losses of approximately 0.5 dB/m. All-optical processing devices typically require a nonlinear phase shift ΔΦ=γPL=π radians for an optical pulse propagating with a peak power P through a fiber length L. The nonlinear fiber response is measured by γ=2πn₂/λA_eff, where n₂ is the nonlinear Kerr coefficient, λ is the wavelength and A_eff is the effective core area. Our experiments demonstrate γ=1500 W^-1km^-1 for core areas of 50 μm². We measure strong self-phase modulation in As-Se fibers formed from high purity materials. Raman gains near 40% were measured using a CW pump power near 200 mW in a 70 cm long fiber with a core area of 50 μm². Applications of these fibers to Raman and parametric amplifiers as well as optical processing devices will be discussed.