Space age lightbulb guys get $21 million more

Luxim, which makes a long-lasting lightbulb that creates light with radio waves--has raised an additional $21 million, according to VentureBeat.

The Sunnyvale, Calif.-based start-up has come up with a way to get rid of the parts inside of high-intensity discharge (HID) lamps that are often the first to fail. (Read our story from last year here.)

Trip the plasma light fantasma.

(Credit: Luxim)

In traditional HID lamps, high voltage pulses pass between two electrodes. The energy creates plasma from the ambient gases trapped inside the bulb and you get light. The electrodes, however, degrade over time. Tungsten splatters off of them and blackens the surface of the bulb.

By contrast, the Luxim LiFi lamp doesn't have electrodes. Instead, a radio-frequency amplifier pumps RF waves to an antenna inside a resonant cavity. The interaction between the waves and the crystal cavity convert trapped gases into a plasma.

"The structure creates a concentrated electrical field in response to a standing wave," explains Julian Carey, vice president of sales at Luxim told us last year.

Crazy, eh?

Luxim's bulbs get 120 lumens per watt. By contrast, many HIDs only get 90 lumens per watt. (Top-end LEDs crank out around 70 lumens per watt). Light sources are big with investors these days.

Panasonic has inserted Luxim's bulb into projection TVs. Luxim's bulbs won't be coming to your home soon because of the cost. Some of the complete lamps are also quite large. CEO Tony McGettigan brings a collection of them to meetings.

The new influx of funds--Luxim earlier landed around $40 million--comes from existing investors like Crosslink Capital and Sequoia Capital. Sequoia started in green technology investing later than most name VC firms, but has been catching up.