Even in these tricky financial times, opto-electronics is offering sufficient funding draw to allow entrepreneurs to start technology companies.
One such firm is cork-based InfiniLED, which emerged from the Tyndall National Institute, becoming a company late in 2010.
Unusually for a start-up “we were in the strange position of spinning-out of the Institute with a number of customers”, chief commercial officer Bill Henry told Electronics Weekly, “and we are going to provide them with products in the very near future.”
The firm’s intellectual property is a way of forming light beams directly from an LED die without added lenses.
It works by micromachining the surface of GaN wafers to leave parabolic mounds. Careful control of dimensions means an LED junction remains on top of each mound, with the parabola focussing its light through the transparent wafer and out the other side.
“Far-field half angle is +/-30°. We get an awful lot of the light inside this: 70% or even 75%,” said Henry. “Stand-alone [conventional] LEDs are +/-60°, with an awful lot of light outside 60°.”
Because of the dimensions, only micro-LEDs can be made like this, with a 15-20µm circle at the base of parabola in which to form the LED.
To form a larger collimated source, dozens of these micro-LEDs can be formed close together in an array, up to 400µm across, for example, said Henry.
Given that a single conventional LED will put a lot more light out of the same area because no room is needed for parabolas, why are potential customers beating a path to InfiniLED’s door?
Henry’s answer is that system cost can be lower when light emerges from the die pre-collimated.
“Even if a standard LED is producing 10-20x more light that our LED, you need to put that light somewhere with good efficiency,” said Henry. “It adds cost to collimate this, and you have to add the cost of developing the optics.”