Abstract: Precision-guided munitions (PGM) play a pivotal role in modern warfare. As such it is important to carry out serviceability checks on critical electro-optical systems particularly those incorporated into precision-guided munitions, laser-warning systems and other military electro-optic systems. These test systems provide functionality checks on military electro-optic systems without the need to disassemble the device under test (DUT) or remove it from the platform. This paper presents new design concepts to build portable electro-optic simulators capable of generating battlefield laser threat signatures to carry out on-line functionality checks on laser sensors used in laser-warning systems and laser seekers in laser-guided munitions. These designs offer one or more advantages over similar commercially available devices and designs discussed in the literature. A prototype using the proposed concept was built and comprehensively evaluated by testing a commercial laser-seeker unit. Test results are presented in this paper.