Osram Opto Semiconductors has introduced InGaN-based direct emission green laser diodes, with wavelengths from 510-530nm, for pico projection and other RGB or green-laser applications. Indium gallium nitride (InGaN)-based laser diodes are straightforward to fabricate in blue-emitting versions, but are more difficult to make so that they emit in green — especially the longer-wavelength green that humans perceive as true green. Early green laser diodes have typically had a slight cyan cast. OSRAM Opto Semiconductors has been pushing the long-wavelength boundary and has now introduced InGaN-based direct emission green laser diodes with wavelengths from 510 to 530 nm for Pico projection and other red-green-blue (RGB) or green laser applications.

Mounted in a tiny TO38icut or TO56 package with integrated photodiode, they combine an excellent form factor with high beam quality, making them suitable as light sources for projectors and show lasers as well as point and line lasers. Two models in particular, PL 520B & PL 520, offer slightly different wavelength ranges at power levels of 30mW or 50mW from a 3.8mm diameter package (at 25°C), with high color rendering and excellent contrast.

Existing small green-laser diodes have been mainly in the form of frequency-doubled diode-pumped solid-state (DPSS) lasers commonly found in the first green laser pointers. These lasers are relatively complicated, containing an infrared pump laser diode to pump the solid-state laser, and a nonlinear optical crystal to frequency double the resulting IR light into the green. Direct emission green laser diodes are an important step toward powerful embedded projectors and signal the end of this complicated method of producing green light by doubling the frequency of infrared lasers.

Here are some of the notable features of Osram’s direct-emission green laser diodes:

High-temperature range and great optical output power of green InGaN lasers
Compared to frequency-doubled lasers, direct green lasers have a high operating temperature range of up to 85 °C without active cooling, whereas single mode blue and green laser diodes deliver up to 80 mW.

High efficiency and long lifetime 
Due to their excellent efficiency (ratio of light produced compared to electric power consumed), the temperature increase experienced by green InGaN lasers during operation is kept to an absolute minimum, allowing them to deliver a long life – up to 10,000 hours at 40 °C.

Leading product performance and innovative packaging 
Thanks to their excellent beam quality, our lasers are ideally suited for the optical imaging of light. Not only that, but their small package size is particularly beneficial to highly compact systems, such as pico projectors.

Projection Applications

• Pico projection
• Business and cinema projection
• Head up display

Display market analyst firm PMA Research has been following the Pico projection market since it’s inception. Their detailed quarterly Pico and Personal Projector Census and Forecast series of reports tracks market trends by a host of specifications – including projector Illumination type.