A hermetic component housing for use with a photonic catheter connected to a photonic pacemaker or other medical system designed for compatibility with Magnetic Resonance Imaging (MRI) procedures. The hermetic housing includes a housing body having a proximal end and a distal end. The body is formed with a hermetically sealed interior for carrying one or more electrical and/or optical components therein. The proximal end of the body is adapted to mount to a distal end of a photonic catheter carrying a fiber optic element or bundle. A hermetic terminal is provided to allow the fiber optic element or bundle to communicate with the body interior. The body can be adapted to mount (or function as) one or more electrodes designed for delivering or sensing electrical signals to body tissue, or it may be adapted to mount no electrodes. The component housing may be implemented by itself at the distal end of the photonic catheter, or it may be used in conjunction with other housings of like or different construction.