Abstract

Continuum radiation from 650 to at least 1800 nm has been generated in silica optical fibers pumped by 100-ps pulses at 1064 nm from a mode-locked Q-switched Nd:YAG laser. The peak spectral power density of the ~100-ps pulses exiting the fiber, as high as 8 W/nm near 1250 nm, is easily sufficient to serve as a broadband source for characterizing fast photodetectors. The 5-m length of continuum generating singlemode silica fiber has a numerical aperture of 0.13. It contains 1.8% P₂O₅ in the cladding and 1.2% in its core; the 6.2-µm core also contains 10% GeO₂. We have tested a number of fibers drawn from the same preform but with differing draw tensions and diameters. Efficient near infrared continuum generation and efficient second harmonic generation seem to be mutually exclusive characteristics of these fibers.

© 1989 Optical Society of America