A modulated semiconductor laser source includes a waveguide on a semiconductor substrate; first and second reflectors; a laser electrode; an optical modulator; and a laser-electrode electrical circuit. The reflectors and a resonator segment of the waveguide define a laser resonator with laser output transmitted through the second reflector. The laser electrode is positioned over the resonator segment and a laser current flows through the laser electrode into the resonator segment to produce optical gain. The modulator receives and modulates the laser output, in response to a primary modulation signal, to produce a modulated output optical signal. The laser-electrode circuit is coupled to the laser electrode and derives from the primary modulation signal a laser-electrode secondary modulation current, optimized to reduce chirp in the modulated output signal, that flows through the laser electrode into or out of the resonator segment in addition to the laser current.