Beam shaping design for fiber-coupled laser-diode system based on a building block trapezoid prism

For the fiber-coupled laser diodes, the high brightness and miniaturization have always been our goals to pursuit. An effective method of achieving a high power and high brightness fiber-coupled laser-diode system has been put forward by ZEMAX software simulation. We designed a simple beam shaping system to improve the beam symmetry and narrow the line width with a trapezoid prism and a set of parallelogram plates. Using this technique, a laser-diode stack consisted of eight bars was coupled into a fiber with a core diameter of 200 μm and a numerical aperture of 0.22. The simulation results demonstrated that the output power can reach 272 W with equalizing brightness of 7.48 MW/(cm2·sr), and the optical-optical efficiency was 85%.