A novel chalcohalide fiber with high nonlinearity and low material zero‐dispersion via extrusion. Issue 9 (26th March 2019) - Zhao, Zheming
Abstract: High nonlinear fibers with low zero‐dispersion wavelength (ZDW), high laser power tolerance and large band‐gap are urgent for all‐optical‐band supercontinuum (SC) generations. Widely used chalcogenide fibers usually have a large ZDW and low laser power tolerance, and thus are not ideal for such purpose. Here, an ultra‐low material ZDW chalcohalide (ChH) glass fiber with high nonlinearity as well as high laser power tolerance has been fabricated successfully via a novel peeling‐off‐extrusion method. The step‐index fiber has double‐cladding structure, the inner cladding is GeGaSe‐CsI glass and the outer one is GeSbS jacket. The core glass has an ultra‐low material ZDW of 3.5 μm and large absorption edge of 2.0 eV. The nonlinear refractive index is 6.67 × 10 −18 m 2 /W @1.55 μm. Broadband SC generation covering 1.05‐13.0 μm is demonstrated in this novel ChH fiber. Such glass fiber with high nonlinearity, wide transparent range, low ZDW and high laser damage threshold is promising for the applications in the mid‐infrared. Abstract : Conventional chalcogenide (ChG) glasses are famous for their unique property in infrared. However, ChG fibers are troubled with intrinsic large material zero‐dispersion‐wavelength (ZDW). Here, a novel Chalco‐Halide (ChH) glass fiber with an ultra‐low material ZDW is created and realized for the first time. These CsI‐containing glasses have lower material ZDW and refractive indices, wider transparent window, better laser damage threshold and larger nonlinear refractive index than As2 S3 glasses.