All-optical noninvasive control of a multi-section semiconductor laser by means of time-delayed feedback from
an external Fabry-Perot cavity is realized experimentally. The role of the optical phase as a specific new control
parameter of this type of delayed-feedback control is stressed. Using phase-dependent feedback from a resonant
plane Fabry-Perot interferometer, the stabilization of unstable steady states and unstable self-pulsations
is achieved, including experimental demonstration of all-optical chaos control. In the latter experiment, optical
chaos is transformed into a regular 12.9 GHz self-pulsation. This result is the fastest realization of chaos control
ever reported. The control is noninvasive, only less than one per mille feedback keeps the stabilized states stable.