Recent Progress Of 638-Nm High-Power Broad Area Laser Diodes In Mitsubishi Electric

Laser based displays have gathered much attention because only the displays can express full color gamut of Ultra-HDTV, ITU-R BT.2020. One of the displays uses the lasers under pulse such as a single spatial light modulator (SLM) projector, and the other does ones under CW such as a multiple SLM projector and a liquid crystal display. Both types require high-power lasers because brightness is the most important factor in the market. We developed two types of 638-nm multi-emitter high-power BA-LDs assembled on phi 9.0-TO, that is, triple emitter for pulse and dual emitter for CW. The triple emitter LD emitted exceeding 6.0 W peak power under 25 degrees C, frequency of 120 Hz, and duty of 30%. At high temperature, 55 degrees C, the peak power was approximately 2.9W. The dual emitter emitted exceeding 3.0W under 25 degrees C, CW. It emitted up to 1.7 W at 55 degrees C. WPE of the dual emitter reached 40.5% at Tc of 25 degrees C, which is the world highest in 638-nm LD under CW to the best of our knowledge, although that of the triple emitter was 38.1%. Both LDs may be suitable for laser based display applications.