Tunable InGaAsP lasers for spectral measurements of high bandwidth fibers

An ultrashort-cavity thin-film laser of InGaAsP, pumped with a mode-locked and
Q
-switched Nd:YAG laser, has been used as the source and an InGaAs/InP p-i-n photodiode as the detector to demonstrate a system capable of measuring bandwidths of 8.5 GHz in single-mode optical fibers. The film laser emits pulses shorter than 10 ps and is tunable over 1700 Å near the chromatic dispersion minimum in fibers.