High power fiber coupled modules based on tapered diode-lasers at 975 nm

With the technological progress of tapered diode lasers brightness and output power of fiber coupled modules can be improved. Tapered diodes bear the potential to achieve high coupling efficiencies in multimode as well as single mode fibers. Within the BRIGHTER Project of the European Union several modules are designed to exploit this potential. The optical systems, the mechanical design and the experimental results of these modules will be presented. A design for a telecom pump module with a coupled power of 50 W in a 50 μm fiber with an NA of 0.22 at 975 nm will be presented. 16 collimated tapered single emitters aligned in four groups of four emitters are combined by mirrors and a polarizing beam splitter and coupled into the fiber. As a variant of this module four emitters are fiber coupled to achieve a power of 12 W of a 50 μm fiber with a NA of 0.13. A single mode fiber coupled module with a maximum output power of 1 W will be presented. Based on a tapered DFB Laser with a wavelength of 1060 nm it serves as a free space communication module. In another application this module is utilized as pump source for second harmonic generation. Equipped with a 975 nm tapered laser diode this module serves as a powerful pump source for Raman amplification.