Abstract: A system for laser-ignition of explosives or the like includes a laser system coupled to an optical fiber for conducting light energy to a window positioned at an end of the fiber remote from the laser system. An explosive charge is contained within an initiator housing on a side of the window remote from the adjacent fiber end. A dichroic film is positioned at the window surface adjacent to the explosive charge, and is constructed to reflect light energy within one wavelength range and transmit light energy within another wavelength range. The laser system is controlled for selectively transmitting light energy at the one wavelength range to test continuity of the laser-fiber-initiator light path as a function of reflections from the dichroic film, and at the other wavelength range to ignite the explosive charge. In one embodiment of the invention, the dichroic film takes the form of a transparent disc having the film deposited thereon.