R&D results on blue lasers: A push of optical output power
OSRAM Opto Semiconductors presents recent laser results at Photonics West 2012 in San Francisco
OSRAM Opto Semiconductors presents recent studies on new designs beyond blue pico lasers. The researchers investigate the power limits of 15 µm wide multimode single emitters at 450 nm emission wavelengths. A maximum efficiency of 29% is demonstrated at optical output power of 1.4 W in TO56 metal can. The maximum output in continuous wave operation at 25° C case temperature is limited by thermal roll-over at 2.5 W.
OSRAM Opto Semiconductors is a key player in semiconductor technology. The company demonstrated blue ridge lasers in TO38 metal can for mobile projection within the project MOLAS of the German Ministry of Education and Research. Since 2008, OSRAM´s blue InGaN laser is in production. Typical applications like pico projection, special lighting, spectroscopy and medical applications need optical output between 10 and 100 mW. However, higher power levels are required to build high luminance light sources with more than 1000 lm for business projectors, automotive head lamps or special lighting. Such light engine uses several blue TO lasers above 1 W combined with laser excited yellow-green phosphor.
“Two key parameters are essential to reach high power levels of single emitters”, said Dr. Uwe Strauss from the laser technology department. “A robust design of the laser facet prevents from catastrophically optical mirror damages and an excellent power conversion efficiency pushes the thermal roll-over to a higher level.” The facet stability is investigated by pulsed operation up to 8 W without any failure. The conversion efficiency up to 29% push the thermal roll-over of the best R&D samples to values as high as 2.5 W in continuous wave operation in TO56 metal can.
For more information please visit Photonics West (San Francisco, USA, 21. – 26. January 2012) and the presentation of Dr. Clemens Vierheilig: “Beyond blue pico laser: development of high power blue and low power direct green” (talk number 8277-77).