A detector system for a fiber optic component is insensitive to stray light. Specifically, the invention comprises a detector chip, which converts received light into an electric signal. A baffle substrate is positioned over the detector chip. This baffle substrate has a transmission port through which an optical signal is transmitted to the detector chip. As a result, light that is not directed to be transmitted through the port is blocked by the baffle substrate. In this way, it rejects stray light that may be present in the hermetic package. A detector substrate is provided on which the detector chip is mounted. This detector substrate preferably comprises electrical traces to which the detector chip is electrically connected. The detector substrate can further comprise bond pads for wire bonding to make electrical connections to the electrical traces.