High-brightness and high-efficiency fiber-coupled module for fiber laser pump with advanced laser diode

High-brightness and high-efficiency fiber-coupled pump module has been developed with newly designed laser diodes and improved spatial optical system. High-power operation was realized by widening laser stripe width. The optical system of the module consists of only spatial multiplexing, not using polarization or wavelength multiplexing technique. Therefore it has advantages that no power loss at a polarization beam combiner or gratings, low material costs of optics, and high excitation efficiency by single wavelength excitation for a fiber laser. The peak power conversion efficiency of the module is 65.6% at 120 W output power, and its efficiency maintains more than 60% up to 220 W at 19 A driving current, and the maximum output power is 252 W at 23 A, at 25 degrees C heat sink temperature. The fiber outside diameter of the module is conventional 125 mu m. Center wavelength of the laser is 915 nm.