Lasers were first integrated into fire control systems in the 1960s and continue to show up as a requirement for many new systems as well as in upgrades to existing systems. In many cases the laser is a critical factor in the performance of the primary mission of the platform. In certain applications, the laser is integrated with a forward-looking infrared (FLIR) detection system and tracker, which provides the means to sight and hold the laser on target. In order for both the laser and the FLIR to operate at peak performance, it is important to understand the specific needs of the two devices and how they may interplay, and address their integration as early as possible in the design process. Both Nd:YAG lasers, used for target designation and rangefinding, and CO2 lasers, used primarily for rangefinding, are currently integrated into fire control systems. FLIR system designers must understand these different laser types and their specific capabilities as they relate to FLIR performance. New weapon system requirements have placed additional utilization demands on the laser-sensor combination to produce an active/passive sensor fusion. For example, chemical warfare point- to-point detection is being addressed through a combined FLIR and differential LIDAR. Likewise, low level navigational hazards are identified via wire sensors for helicopters. Target detection is further complemented with laser-based vibration sensors. Sensor fusion is rapidly emerging to solve future air-to-ground, ground-to-air, and ground-to-ground mission requirements.