Lasing and supercontinuum generation in single-crystalline fibers

Single crystal fibers doped with Er or Tm and clad with a sapphire sol-gel were tested for both laser performance and super-continuum generation. Laser performance was explored for multiple sol-gel cladding deposition cycles (0 to 5) in addition to variable concentration (0.25% to 3%). A single sample showed exemplary performance (2% Tm with 3 deposition cycles) achieving 44.5% slope-efficiency. Super-continuum generation was compared in pure and doped fibers of both 150μm and 50μm diameters at five different pump wavelengths with an 80 fs source. Super-continuum was generated covering 1.5 octaves (790 nm pump) and <2.5 octaves (1645 nm pump) with a threshold pulse energy of 0.4 μJ (5 MW peak power).