Reduction of beam divergence angle in laser-diode arrays with large smiles using a dual-beam transformation system

摘要

Two new angled half-beam transformation systems (BTSs) for the reduction of the beam-divergence problem in laser-diode arrays with large smiles are investigated. Both simulations and experiments show that the angle of divergence of laser-diode arrays with the parabola-shaped smile and the S-shaped smile can be reduced by more than 37% and 23% respectively, when two angled half-BTSs are used in front of the laser-diode array. Furthermore, a fiber-coupling module, with a 400 mu m core-fiber and two angled half-BTSs, is fabricated. The optical/optical coupling efficiency increases to more than 85%, which is an improvement by more than 4% over laser diodes that use a full-BTS.