Random lasing from optical fibers with phase separated glass cores.

A novel random laser, integrating a passive optical fiber with a phase separated aluminosilicate core-silica cladding as the feedback medium, is proposed and presented. The core exhibits greatly enhanced Rayleigh scattering, therefore requiring a significantly reduced length of scattering fiber (4 m) for lasing. With a Yb-doped fiber as the gain medium, the fiber laser operates at 1050 nm with low threshold power and possesses an output that can be amplified through conventional means. Furthermore, the laser was found to have a high degree of spatial coherence, spectral broadening with increasing input power, and temporal spectral variation. The facile setup and results herein pave the way for further study and applications based on low threshold random fiber lasers.