An electro-optic modulator modulates light in response to a life-form bio-potential to provide a bio-potential modulated light output. Modulation can be carried out as a result of capacitive coupling with the bio-potential. Phase, polarization, and intensity light modulation can be used. The light output can then be converted to electronic form for further processing. An optical power splitter is used to split light into multiple portions that are converted to electrical form. A pilot tone is used to achieve high sensitivity and synchronize multiple electro-optic modulators while phase modulation can be used to reduce noise in the bio-potential signal. Low-coherent light may be used as the light source. A housing is provided that can be hermetically-sealed and provided with electro-magnetic shielding.