Recently, Uwe Strauss from Osram Opto Semiconductors has demonstrated the company’s improved green laser performance that are fabricated on the conventional plane of GaN,at the ninth International Conference on Nitride Semiconductors.
According to Strauss , these lasers will target pico-projectors, where they can combine with red and blue equivalents to provide a lighting source with a small footprint that is free from a focusing element.
Strauss introduce that the green source in a pico-projector producing a 100 lumen brightness must meet the requirements as following: an emission wavelength of 515 nm; an output power of at least 50 mW; a wall plug efficiency of 5 percent or more; and, in both the lateral and vertical directions, a single mode output. If a shorter wavelength source is used – for example, a 505 nm laser – the power output requirements are higher.
In fact, Osram has exceeded these requirements in the lab,. It's best lasers produce 70 mW at 522 nm with a wall plug efficiency of 5-6 percent, and have a spectral width of 1.8 nm. Furthermore, reliability – defined as the time taken for the operating current to increase by 30 percent – is more than 1000 hours.