Firing systems typically incorporate isolation-based architectures that are established by the safety themes of particular weapon systems. Robust electrical diversion barriers are implemented to isolate energy from detonation-critical components until the event of intended use of the system. An optical trigger assembly is being developed to enhance the safety of new firing systems. It couples a fast trigger signal through an exclusion region barrier without compromising the integrity of the barrier in abnormal environment situations. A laser diode generates an optical pulse that is coupled through a sapphire stub to a photoconductive semiconductor switch (PCSS). The PCSS drives a vacuum switch tube to complete the triggering chain in the firing system. A general discussion and comparison of triggering technology options, and the design characteristics and performance parameters of the specific optical trigger point design are presented in this paper.