InGaN Power Laser Chips in a Novel 50W Multi-Die Package

摘要

In this paper we report recent developments on high power blue laser chips. Reduction of internal losses as well as optimized thermal management had been essential to increase optical output power. R&D samples with average performance of 3W optical output at junction temperatures of 130°C are demonstrated. The chips are suitable for use in a novel multi chip housing: For the first time up to 20 blue laser chips have been packaged into one compact housing resulting in the first InGaN laser device with optical output ＞ 50W. The highly integrated package offers a unique small size. The outer dimensions of the package are 25.5mm × 35mm with an emitting surface of 16mm × 16.5mm. Therefore the complexity of optical alignment is dramatically reduced and only a single sheet multi lens array is required for beam collimation. Besides the unique technical performance the multi-die package offers significantly lower assembly costs because of the reduced complexity and assembly time. The butterfly package contains 4 bars with up to 5 multimode laser chips in series connection on each bar operating at 2.3A. The typical module wavelength is 450nm +/- 10nm. At a case temperature of 50°C the R&D samples achieve efficiencies of typ. 30% and an optical output power of 50W corresponding to an electrical power consumption of ～165W. This new technology can be used for high performance light engines of high brightness projectors.