Development of multicore and tapered chalcogenide fibers for supercontinuum generation

Abstract

The dramatic spectral broadening of an electromagnetic radiation as it propagates through a nonlinear medium is called Supercontinuum generation. Supercontinuum generation is indeed regarded as one of the prominent phenomenon in nonlinear optics and photonics with burgeoning applications in various fields such as spectroscopy, early cancer diagnostics, gas sensing, food quality control, uorescence microscopy e.t.c. Supercontinuum generation in optical fibers is however associated with three fundamental challenges: minimization of input power threshold, maximization of output power as well as output spectrum of a supercontinuum. Two unique fabrication approaches namely "Direct tapering" and "Multicore fibers" were proposed to address the aforementioned challenges. Chalcogenide nanowires were fabricated via direct tapering of chalcogenide glasses, and spectral broadening with extremely low peak power of 2 W was demonstrated. Multicore array of chalcogenide step index fibers were also fabricated using a new method. The fabricated step index fiber has a diameter 1.35 m which was engineered to have a zero dispersion wavelength (ZDW) around 1100 nm with a pump of center wavelength at 1550 nm .Using split step Fourier method, it was shown that the fiber possesses a great potential for severe spectral broadening. Supercontinuum generation with the as drawn fiber, encountered challenges as well as proposed solutions were demonstrated and discussed.