Complementary modulation involving dynamic carrier heating along with carrier injection is reported as means for the picosecond pulse shaping in a gain‐switched semiconductor laser. By numerical simulation based on the earlier developed model of a GaInAsP/InP laser operating in the 1.55 &mgr;m wavelength, we show that it is possible to produce the ideal‐shaped low‐chirp high‐intensity optical pulses at multi‐Gbit/s repetition rate. A three‐terminal laser device, in which hot electrons with well‐defined and tunable energy are injected by resonant tunneling, is proposed to implement this modulation technique. ©1995 American Institute of Physics.