Characterization of Tm/Yb doped phosphate microsphere fibre lasers for potential sensor applications

In this paper Tm/Yb doped microspheres have been successfully created through melting the ends of fibre cores etched from single mode Tm/Yb fibres designed and fabricated specifically for the laser emission centred at mid-infrared region. When coupled with a fibre taper, a microsphere fibre laser cavity can thus be configured creating a system when pumped by a ~1600nm laser source using a monochromator to monitor the spectral characteristics of the laser output produced. The performance and characteristics of the Tm/Yb microsphere lasers are discussed in detail in the paper. The laser has shown low threshold in terms of the pump power making it well suited to potential optical fibre sensor applications.