Efficient and broadband optical parametric four wave mixing in   chalcogenide-PMMA hybrid microwires
  The recent development of devices based on novel nonlinear materials like chalcogenides (ChGs), silicon (Si) and other semi-conductors has revolutionized the field of nonlinear photonics [1,2,3]. Among the nonlinear effects observed in these materials, four-wave mixing (FWM) is the process that finds the most applications including wavelength conversion [4], optical regeneration [5,6], optical delay [7], time-domain demultiplexing[8], temporal cloaking[9] and negative refraction[10]. Although FWM has been observed in several media including chalcogenides [11,12,13,14], silicon[15, 16], bismuth [17] and silica [18,19], there is a continued quest for devices that realize efficient and broadband FWM while offering compactness, low-power consumption and compatibility with optical fibers. Here, we demonstrate the fabrication of 10 cm long polymer cladded chalcogenide (As2Se3) microwires to realize FWM-led sub watt threshold (70-370 mW) wavelength conversion with a 12 dB bandwidth as broad as 190 nm, and conversion efficiency as high as 21 dB. This represents a 3-30 \times increase in bandwidth and 30-50 dB improvement in conversion efficiency over previous demonstrations in tapered and microstructured chalcogenide fibers [11,13,14]. These properties, combined with low loss (< 4 dB), ease of fabrication, and the transparency of As2Se3 from near to mid infrared regions (1 15 \mum) [20] make this device a promising building block for lasers, optical instrumentation and optical communication devices. 
Raja Ahmad, Martin Rochette
physics.optics