High power diode laser arrays, fiber-coupled arrays and 2-D stacks
There is an ever increasing demand for more power from high-power (> 0.5 W) diode lasers (HPDLs), in the near-IR wavelength range of 790-1000 nm. This is not only to improve or enhance existing applications, but to enable new applications suited for commercial use in the area of printing, medical diagnostics/therapeutics, materials processing, communications, compact and reliable solid-state lasers, etc. Until recently commercial devices with good reliability were limited to typical CW output powers of ~1 W from 100 μm aperture to ~20 W from a 1 cm linear array, though much higher powers have been reported in research devices. In quasi-CW (QCW), i.e., pulsed operation, up to ~100 W peak power has been the standard for low duty cycle applications. Through improvements in epitaxial growth, design and processing, and packaging, we are continuing to push reliable operation to much higher power levels, especially for linear arrays and stacks, for both CW and high duty cycle pulsed operation, using the GaAs/AlGaAS/InGaAs material system in the 800-915 nm wavelength range. In addition, initial data indicates that these HPDL are expected to have similar lifetimes as current standard 20 W linear arrays.
We believe these high-power diode laser arrays and 2-D stacks will find new uses in material processing, medical applications, and pumps for solid-state lasers. High-power fiber-couped devices will significantly enhance the potential of existing graphics applications and open up new applications, e.g. dual-clad fiber laser pumps for single-mode amplifiers in telecommunications.