A method for operating an optical modulator that includes a modulator optical waveguide formed on a substrate, the method comprising: (a) launching an continuous-wave input optical signal to propagate along the modulator optical waveguide, the input optical signal being characterized by an input optical power level and an optical signal wavelength; and (b) applying an electrical modulation signal (BIAS 2; RF) to a modulator electrode positioned over a semiconductor modulator active region of the modulator optical waveguide so as to modulate an optical transmission level of the input optical signal through the modulator resulting in a modulated output optical signal emitted from the modulator, characterized in that: (c) the electrical modulation signal (BIAS 2; RF) is applied at positive voltage; (d) an electrical modulation signal level that causes charge carriers to be injected into the modulator active region results in an increase of the optical transmission level, relative to the optical transmission level with a positive modulator bias voltage level applied to the modulator electrode that results in carriers being neither injected into nor extracted from the modulator active region with the input optical signal propagating along the modulator optical waveguide; and (e) an electrical modulation signal level that causes charge carriers to be extracted from the modulator active region results in a decrease of the optical transmission level, relative to the optical transmission level with the positive modulator bias voltage level applied to the modulator electrode that results in carriers being neither injected into nor extracted from the modulator active region with the input optical signal propagating along the modulator optical waveguide. (a) launching an continuous-wave input optical signal to propagate along the modulator optical waveguide, the input optical signal being characterized by an input optical power level and an optical signal wavelength; and (b) applying an electrical modulation signal (BIAS 2; RF) to a modulator electrode positioned over a semiconductor modulator active region of the modulator optical waveguide so as to modulate an optical transmission level of the input optical signal through the modulator resulting in a modulated output optical signal emitted from the modulator, (c) the electrical modulation signal (BIAS 2; RF) is applied at positive voltage; (d) an electrical modulation signal level that causes charge carriers to be injected into the modulator active region results in an increase of the optical transmission level, relative to the optical transmission level with a positive modulator bias voltage level applied to the modulator electrode that results in carriers being neither injected into nor extracted from the modulator active region with the input optical signal propagating along the modulator optical waveguide; and (e) an electrical modulation signal level that causes charge carriers to be extracted from the modulator active region results in a decrease of the optical transmission level, relative to the optical transmission level with the positive modulator bias voltage level applied to the modulator electrode that results in carriers being neither injected into nor extracted from the modulator active region with the input optical signal propagating along the modulator optical waveguide.