Cascaded Stimulated Raman Scattering in a Chalcogenide Optical Fiber

Stimulated Raman scattering (SRS) is a nonlinear effect in the media which can transfer a fraction of power from one optical field to another and whose frequency is downshifted by an amount determined by the vibrational modes of the medium. When Raman gain of the optical fiber is high and pump power into it is sufficient, cascaded SRS effect can be achieved. In this paper, a low-loss chalcogenide optical fiber was designed and fabricated based on As-S glass, and a 16 m long fiber was experimentally used to enhance Raman gain for boosting cascaded SRS generation. A nanosecond laser at ~1545 nm was used as the pump source and mid-infrared cascaded SRS up to eight orders was observed.