Scheme
Laser diode stacks consists of vertically arranged laser bars or single emitters. Thus the overall power scales with the number of emitters to power in the kW region.
Applications
- Pumping of solid state, fiber and alkali-gas lasers (e.g. material processing and high-energy-class solid state systems)
- Direct material processing (e.g. sources for spectral beam combined systems)
- Free-space communications
- Printing
- Medical technology
Chip technology
- Semiconductor layers by means of MOVPE
- Monolithic gratings via surface etch technology or two step-epitaxial techniques
- Contact windows by
- projection lithography
- implantation and isolating layers
- deposition of metalization
- Thinning
- Scribing, breaking and cleaving
- Facet coating and passivation with extremely long lifetimes
Assembly
- Soldering of bars and large-aperture single emitters on passive CuW heat sinks
- Stacking of CuW heat sinks and fixing using AuSn solder suitable for extremely long lifetimes
- Attaching of FAC lenses on the stack
- Coupling into fiber
Typical data
- QCW operation tP = 1 ms f = 10...200 Hz
- Tailored single emitters with 1.2 mm aperture
- reliable output power > 120 W
- power density ~ 1 kW/cm
- lateral far field 12° (95% power)
- efficiency > 60%
- Stack of 28 bars and FACs
- output power 3.5 kW
- simple and efficient coupling into fibers possible
- vertical divergence (> 95% power level) < 2 mrad
- vertical beam parameter product < 90 mm mrad
- lateral divergence (> 95% power level) < 210 mrad
- lateral beam parameter product < 90 mm mrad