An InGaAsP/InP separate-confinement double heterostructure having a broad g
ain profile was used to fabricate superluminescent diodes having high optic
al power (40 mW), a broad radiation spectrum (65 nm at half-width), and low
percent modulation (< 1%). Using a cw pump current of 150 mA, 1 mW of supe
rluminescence radiation was obtained at the exit from a single-mode optical
fiber. (C) 1999 American Institute of Physics. [S1063-7850(99)00408-5].