Jena, Germany - Jenoptik's Laser & Materials Processing Division will introduce new semiconductor lasers with an even higher efficiency rate at this year's Laser World of Photonics (Munich, May 13 to 16). These new semiconductor lasers are useful pumping sources for fiber lasers and disk lasers. Due to the laser's high efficiency of over 70% with very little beam divergence, they guarantee high output power and high brilliance along with long life and low cost.
The 9xx nm single emitters with 90 µm aperture have 12 W output. The efficiency at this output level and a mounting on a passive heat sink is 64%. The highest obtainable efficiency is 74%. The beam divergences of 26° in fast axis and 6.5° in slow axis direction (full width half maximum of the 12W peak) makes them a good choice for coupling in a 105 µm fiber.
The 9xx nm mini-bars are a great beam source: they combine the high brilliance of single emitters with the low mounting costs of bars. The mini-bars contain five emitters of 90 µm width and 1000 µm spacing each. With maximum 55 W output power and being mounted on a passive heat sink, the highest efficiency is 69%. The beam divergences are the same as those of the single emitters.
The new laser bars are available for wavelengths of 915, 940, and 955 nm and, with low filling factor, of 976 nm. They are useful pumping sources for fiber and solid-state lasers, but also a very good solution for diode direct applications.
The higher efficiency is particularly evident from the full bars for 976 nm with a filling factor of 20%. These bars, mounted on passive heat sink, score 66 percent efficiency at 80 W output power. The beam divergences at this output level are 23° in fast axis direction and 6.5° in slow axis direction (full width half maximum of the peak). The degree of polarization of these TE-polarized lasers is better than 97%.
The bars for the 938 nm wavelength and 50% filling factor have been improved for the optical pumping of disk lasers. Mounted on passive heat sinks, their efficiency is 64% at 200 W output power; at 250 W output power, the efficiency is still more than 60%.