relies on advanced training in technical areas with a basis in science, technology, engineering, and mathematics (STEM), which are precisely the areas in which it is becoming more difficult to find continued optics and photonics education in the United States. The ability of U.S. defense forces to leverage technology for dominance while using a small force is also threatened by an ongoing migration of optics and photonics capabilities to offshore manufacturing sites. This means that the United States may lose both first access and assured access to new optics and photonics defense capabilities.
Although conventional night-vision imagers have become commodities available to anyone with money, more sophisticated optical-based surveillance systems have made major progress in the past decade and provide a great opportunity. A number of very-wide-field-of-view passive sensor systems have been developed and are discussed in this chapter. It is now possible by using such systems to view large areas with moderate to high resolution, especially during the day. Large portions of a city can thus be continuously monitored and the data from the system stored. If something of interest occurs, it is possible to re-examine that event to determine exactly what happened. Once areas of interest have been detected, it would be useful to have exquisite detail in certain critical areas, highlighted by the wide-area detection sensor. There have recently been long-range identification demonstrations using active electrooptical (EO) systems called laser radar, or ladar. Although synthetic aperture radar (SAR) has been around for decades, it is only recently that synthetic aperture ladar systems have been flown. These are briefly discussed below. Multiple sub-aperture-based, potentially conformal, active sensor developments are also discussed. This is a developing technology that will allow lighter-weight, long-range imaging systems that can also be applied to laser weapons. After an object has been detected and identified, it may be recognized as a threat that has to be dealt with. “Speed-of-light” weapons are ideal choices for certain applications, such as for a boosting missile. These laser weapons can destroy a boosting ballistic missile, causing whatever warhead is on the missile to fall back on the nation that fired the missile. Recently the Airborne Laser Test Bed (ALTB)3 shot down a boosting ballistic missile with an onboard laser for the first time. Although this was a highly successful test, it was done with a chemical laser, using a mixture of oxygen iodine as the gain medium. There is strong interest in and great potential for laser weapons that run on electricity. If sufficient electricity can be generated from onboard fuel, one could use the same fuel, already in use. Multiple all-electric laser options are briefly discussed below.
The three areas just referred to have made major progress over the last decade,
3 More information on the Airborne Laser Laboratory is available at http://www.fas.org/spp/starwars/program/all.htm (accessed November 22, 2011) and http://boeing.mediaroom.com/index.php?s=43&item=1075 (accessed November 7, 2012).