A control circuit coupled to a light source and an optical modulator receives an electrical modulating signal with alternating active and idle temporal segments; the active temporal segments encode corresponding information. A portion of a source optical signal produced by the light source is transmitted by the modulator as the output optical signal. During idle temporal segments, the light source produces a non-zero source idle power level, and the modulator transmits at a constant idle transmission level. During active temporal segments, the light source produces a source average active power level, the modulator transmits at an average active transmission level that is higher than the idle transmission level, and the output optical signal is modulated in accordance with the electrical modulating signal, so that each active temporal segment of the output optical signal encodes the information of the corresponding active temporal segment of the electrical modulating signal.