LONDON — Startup company Ceravision Ltd. (Milton Keynes, England) has said it has invented a microwave-powered light bulb that is more efficient than filament or fluorescent lighting and with a long stable lamp life. The company said it has prototypes available for evaluation by lamp and electronics manufacturers.

The Continuum 2.4 system comprises a microwave source and power amplifier, a microwave interface unit and a low-loss dielectric resonator with an interior void where noble gas is excited to produce light.

One of the breakthroughs claimed by Ceravision is the ability to prevent high levels of microwave power being reflected back to the source and damaging it at switch on. The microwave interface unit limits less than 0.5 percent of incident microwave power is reflected back, the company said.

Instead the output is launched via a metal antenna into a metal-coated low-loss dielectric resonator. The mechanical dimensions of the resonator determine the ultimate performance of the lamp system and where the microwave energy will be focused. At the focal point the resonator has a cavity into which the electrode-less "burner" is inserted.

According to information contained at Ceravision's website the microwave light has an efficiency of more than 50 percent, compared with fluorescent tubes' efficiency of about 15% and traditional light bulbs, which emit only about 5 percent of their enery conversion as light, the vast majority being emitted in the form of heat. In addition, unlike compact fluorescent tubes, Continuum 2.4 contains no mercury.

Ceravision has received an undisclosed amount of backing from investors including Saad Investments and ASA Consultants.

The 2.4 in the name of the technology is thought to refer to the frequency at which the microwave source operates, 2.4-GHz. It was not discussed on the company's website as to whether this could create potential problems with 3G or wireless LAN transmissions.

However, the company did say on the website that the source frequency "can be any approved licensed or unlicensed frequency."

"Continuum 2.4 will change the way that commercial and industrial lighting develops. There’s simply no other environmentally friendly bulb on the market that delivers the quality of light that Continuum™ 2.4 delivers with such a low manufacturing cost," said Tim Reynolds, chief executive officer of Ceravision, in a statement.

"Its capabilities to provide a widely selectable wavelength range, extremely high levels of efficacy and long life, combined with a small emission area, make this an illumination product designer's dream. This technology is truly set to be the biggest revolution to the lighting industry since the invention of the filament lamp, and even the high power LED," said Mike Hanney, technical director of Polymer Optics, a maker of plastic lenses, in the same statement.