Generation of a continuum extending to the midinfrared by pumping ZBLAN fiber with an ultrafast 1550-nm source

Pulses from a commercial erbium-doped fiber laser are coupled into a standard silica fiber and a standard fluoride fiber connected in series. By cascaded Raman soliton self-shifting, a continuum extending to a wavelength of /spl sim/3 μm is generated. The total average power emitted in the 1.8-3.4-μm range is 5 mW. Throughout the 1.4-2.9-μm range, the average spectral power is /spl sim/4 μW/nm and higher, corresponding at 2.9 μm to a spectral radiance approximately 4600 times that of a 3000 K blackbody.