Coupling multi-beam laser diode to multimode fiber by wedge prism combiner

For high-power fiber-lasers, high power and high brightness have always been the goals pursued in the field of industry and defense. Based on the beam propagation principle, a novel lens combination of right-angle prisms and trapezoidal prisms is designed to realize the homogenized alignment of two rows of semiconductor laser array spots. The beam propagation and coupling efficiency of the system are analysed in detail using numerical analysis and ZEMAX, respectively. The results show that the output power of the fiber-laser reaches 620.9 W at 35 A current with 86.24 % coupling efficiency, which matches the simulation result of 89.65 %. Furthermore, the effects of the variations of different degrees of freedom of the optical elements on the coupling efficiency, such as angle and displacement, are further analysed to provide a reliable basis for the development of coupling devices.