A testing system for a modulator includes a radio frequency (RF) generator, an optical power meter, and an electrical power meter. The RF generator is configured to generate and provide a first plurality of RF signals and a second plurality of RF signals, wherein the first plurality of RF signals and the second plurality of RF signals are associated with a plurality of frequencies. The optical power meter is configured to measure an optical power of an output optical signal, which is modulated by the modulator based on the first plurality of RF signals, to facilitate determination of a transmission response measurement of the modulator for each frequency of the plurality of frequencies. The electrical power meter is configured to measure a portion of each RF signal of the second plurality of RF signals to facilitate determination of a reflectance response measurement of the modulator for each frequency.