Evolution of noise-like pulses to watt-level all-fiber supercontinuum in compact all-normal dispersion fiber laser using nonlinear polarization rotation

Noise-like pulses (NLPs) and supercontinuum (SC) in all normal dispersion (ANDi) fiber lasers are experimentally demonstrated to have excellent characteristics. This all-fiber SC laser source has generated 4.1 W of maximum average optical output with a broad spectrum from 900 nm to 1700 nm. The compact ytterbium-doped fiber ring laser (YDFL) mode-locked was induced by the nonlinear polarization rotation (NPR) mechanism. The YDFL generates NLPs with a pulse energy of 78 nJ, a 3-dB spectral width of 73 nm, and a pulse rate of 13.6 MHz. From the NLPs states, the input power was then increased to generate a supercontinuum with a flat 5-dB spectral width > 320 nm. This compact intracavity SC fiber laser shows its benefits of simple structure, short fiber, low cost, and ease of fabrication, which provide an SC source for multiple practical applications.