April 21, 2009 Boeing has won a U.S. Navy contract worth up to $163 million to develop the Free Electron Laser (FEL), a weapon system that the company says "will transform naval warfare in the next decade by providing an ultra-precise, speed-of-light capability and unlimited magazine depth to defend ships against new, challenging threats, such as hyper-velocity cruise missiles." The envisioned level of precision would enable U.S. Navy ships to deliver nonlethal or lethal force to targets with power and minimal collateral damage.
A FEL shares the same optical properties as conventional lasers - it emits a beam consisting of coherent electromagnetic radiation which can reach high power - but it uses some very different operating principles to form the beam. Unlike gas, liquid, or solid-state lasers such as diode lasers, in which electrons are excited in bound atomic or molecular states, FELs use a relativistic electron beam as the lasing medium which moves freely through a magnetic structure, hence the term free electron. The free-electron laser has the widest frequency range of any laser type, and can be widely tunable, currently ranging in wavelength from microwaves, through terahertz radiation and infrared, to the visible spectrum, to ultraviolet, to soft (low-energy) X-rays.
To create the FEL, a beam of electrons is accelerated to relativistic speeds passing them through a FEL oscillator / undulator. The acceleration of the electrons along this path results in the release of a photon (synchrotron radiation). Importantly, the wavelength of the light emitted can be readily tuned by adjusting the energy of the electron beam or the magnetic field strength of the undulators. The FEL requires the use of an electron accelerator typically powered by klystrons, which require a high voltage supply.
The FEL’s can achieve very high peak powers and are highly desirable - due to their tunability - in several disciplines, including medical diagnosis and non-destructive testing. FEL wavelengths have been used in successful surgery to cut and remove tissue such as removing brain tumors, for optic nerve surgery, and for the melting of fats with no damage to overlaying skin. The later could lead to their use in the selective destruction of sebum lipids to treat acne, as well as targeting other lipids associated with cellulite and body fat as well as fatty plaques that form in arteries which can help treat atherosclerosis and heart disease.
Military use of FEL’s
FEL technology is considered by the US Navy as a promising technology for an antimissile directed-energy weapon. A directed-energy weapon (DEW) is a type of weapon that emits energy in an aimed direction without the means of a projectile- like an intense emission of laser light. FEL’s are capable of achieving the megawatt power level the Navy requires for ship defense.
Boeing says the contract, which will begin with an initial task order of $6.9 million, is significant because it will be a cornerstone of the Navy's plan to incorporate directed energy systems into its future all-electric ship architecture. Under the task order Boeing will complete the preliminary design of the electric-powered Free Electron Laser, the key step toward building a FEL prototype for realistic tests at sea. Boeing will partner with U.S. Department of Energy laboratories, academia and industry partners to design the laser.
Boeing has researched free-electron lasers since the early 1980s, and now believe this technology is ready to move from the laboratory to a prototype suitable for testing. Other high-energy laser system applications provided by Boeing include the Airborne Laser, the Advanced Tactical Laser, the High Energy Laser Technology Demonstrator, Laser Avenger, the Re-deployable High Energy Laser System and the Tactical Relay Mirror System.