Short fiber lasers produce record power/length of 1.33W/cm

The experimental results achieved with short (7cm) phosphate fiber lasers which generate more than 9.3 W multimode and 4 W single mode output power were presented. The power generated per unit fiber length of 1.33W/cm represents a record in the fiber laser. The development of on-chip, watt-level single-frequency light sources in the 1,550 nm wavelength band. The maximum output power of a centimeters long laser was limited for the most part to the milliwatt level because of the difficulty of increasing ion doping concentrations in the fibers and of achieving high pump absorption with a double-cladding pump. A new side-pumping scheme compatible with short fiber lasers was demonstrated. The side-pumped laser constitutes a 12 cm long circular fiber.