A readout circuit for an amplitude modulating sensor includes a first and second wavelength light source; an optical coupler coupled to receive a first light signal from the first wavelength light source and a second light signal from the second wavelength light source; a frequency selector that allows for the first light signal to pass to the amplitude modulating sensor; and a detector system coupled to the optical coupler to receive the first light signal and the second light signal after the first light signal is modulated by the amplitude modulating sensor and independently detect the two signals. The detector system generates electronic signals representing the modulated first light signal and the second light signal and removes a common mode signal of the modulated first light signal and the second light signal, removing common mode noise or attenuation in the modulated first light signal.