Many lasers become one in Lockheed Martin's 30 kW fiber laser
By David Szondy
February 2, 2014
In another step forward for laser weapons that brings to mind the Death Star's superlaser, Lockheed Martin has demonstrated a 30-kilowatt fiber laser produced by combining many lasers into a single beam of light. According to the company, this is the highest power laser yet that was still able to maintain beam quality and electrical efficiency, paving the way for a laser weapon system suitable, if not for a Death Star, for a wide range of air, land and sea military platforms.
The test was the culmination of an internally-funded research and development program based around a process that the company calls Spectrum Beam Combining. Though laser weapons have been successfully tested in the past, Lockheed says that even though such systems could acquire, track, and destroy targets, they lack practicality as a tactical weapon because the inefficient nature of the lasers resulted in them being too large, needing too much power, and being difficult to cool.
Spectrum Beam Combining seeks to overcome these deficiencies by means of fiber laser modules. Fiber lasers are lasers where the active gain medium consists of an optical fiber doped with a rare-earth element, such as erbium, ytterbium, neodymium, or others. The optical fibers are flexible, so the laser can be thousands of meters long for greater gain, yet takes up very little space because it can be coiled like a rope, and the large surface to volume ratio means that it's easy to cool. In addition, fiber laser are very durable and project a high-quality beam.
But the key feature for Lockheed is that fiber lasers are as easy to direct as water through a hose. Spectrum Beam Combining involves taking the laser beams from a number of fiber laser modules – each one generating light at its own, unique frequency – and passing them through a combiner to produce a single, powerful laser beam of "near-perfect" quality that uses fifty percent less electricity than an equivalent solid-state laser.
"Lockheed Martin has opened the aperture for high power, electrically driven laser systems suitable for military applications," said Dr. Ray O. Johnson, senior vice president and chief technology officer of Lockheed Martin. "Advancements in available laser components, along with the maturity and quality of our innovative beam-combining technology, support our goal of providing lightweight and rugged laser weapon systems for use on military platforms such as aircraft, helicopters, ships and trucks."
Source: Lockheed Martin