According to GlobalSecuity.org, Boeing has been busy creating invisible directed energy weapons:
The Advanced Tactical Laser can place a 10-centimeter-wide beam with the heating power of a blowtorch on distant targets for up to 100 shots. The Advanced Tactical Laser can produce a four-inch-diameter beam of energy that can slice through metal from a distance of 9 miles….
…The ATL is not subject to direct attack by small arms or shoulder-launched anti-aircraft missiles. In fact, it can be far enough away that its action is almost covert. The laser beam makes no sound and is not visible. The effect of the beam may not be easily associated with a presence of an aircraft several miles away!