More efficient directed-energy weapons are among potential applications of high-power solid-state lasers to be developed under the USDefense Advanced Research Projects Agency's super-high efficiency diode source (SHEDS) programme. Alfalight has received a contract potentially worth $5.3 million under the SHEDS programme to demonstrate dramatic increases in the efficiency of semiconductor diode laser bars.

Diode-pumped solid-state lasers have an overall electrical-to-optical power conversion efficiency as low as 10%, so a weapons-grade 100kW laser requires 1,000kW of power and generates 900kW of heat. Madison,Wisconsin-based Alfalite says its aluminium-free active region diode laser bars achieve over 50% efficiency. The aim is to increase this to 65% in the first 18 months of the programme, with a target of 80% in the following 18 months.

Northrop Grumman and Raytheon won US Air Force Research Laboratory contracts last year to demonstrate 25kW-class diode-pumped solid-state lasers by the end of 2004.

Source: Flight International