Launch Counter: U.S. Army Considers Quantum Cascade Lasers to Protect its Aircraft
The Army’s choice of updated IRCM systems is expected in a few months, which is why several defense contractors developing this technology are making a serious push for consideration at this week’s annual Association of the United States Army meeting and expo in Washington, D.C.
Whereas the U.S. military, led by the Army, has for decades used IRCM technology weighing several dozens of kilograms to disrupt heat-seeking missile attacks, the Army is hoping a newer, lighter approach called Common Infrared Countermeasures (CIRCM) will more reliably protect a wider range of aircraft. To meet the Army’s 38.6-kilogram CIRCM weight limit, some contractors are turning to solid-state quantum cascade lasers as a means of disrupting a missile’s guidance system and throwing it off course.
Quantum cascade lasers, first developed at Bell Laboratories in 1994, are semiconductor lasers that emit in the mid- to far-infrared portion of the electromagnetic spectrum. Such lasers can be made smaller, lighter and more reliable than the optical parametric oscillator (OPO), the multiband laser OPO, and the fiber laser–pumped systems used in current IRCM systems. This is because a quantum cascade laser directly converts electrons entering the semiconductor to photons. (Multiple photons can even be generated by a single electron, improving the system’s efficiency.) Other types of lasers require more complicated setups for generating the wavelengths needed to target missile-guidance systems. In addition, semiconductor lasers can be manufactured at about 4.5 millimeters in length in high volumes on wafers similar to the way transistors are produced. A conventional glass OPO laser could be up to half a meter long.