Laser light stimuli for maritime warning and repulsion: Evolving concepts and capabilities

Small watercraft can carry a lethal threat to port assets and vessels. A new generation of lasers is currently being evaluated for non-lethal deterrence to protect vessels and pier-side assets in littoral environments. These lasers have evolved from their predecessors in several respects. First, they are more compact and powerful. Second, many new-generation lasers can produce different wavelengths and temporal profiles. Next, the latest laser systems include range-finders to shut down the beam if it points at a target that lies within the Ocular Hazard Range. Finally, the lasers can be employed as stand-alone devices or as the mildest of several force options in a scalable directed-energy system; if the target continues approaching, it can be concluded that he is hostile, and this clears the way for more forceful measures aboard the defended asset. As with any device, operational limitations remain. Certain signals may be perceived ambiguously by the target, particularly if they do not appear bright (a factor in daylight conditions) or do not project the red-orange hues almost universally understood to convey warning. In addition, the non-injurious design concept is complicated if the target might be using optical aids, which change the laser's range and hazard characteristics. Considered in sum, new-generation lasers offer the option to qualify the intentions of the target, discourage approach, and encourage the target to go away by inducing discomfort or sensory interference. If these objectives are achieved, the encounter will represent a successful security engagement and a de-escalation or elimination of threat.