In order to study the output far field characteristics of optical fiber coupled laser diodes, several kinds of fiber coupling structures based on single emitting diode laser chip were simulated by ZEMAX optical design software, the analysis on the far field characteristics were conducted. The simulation results show that the far-field output distribution of a single emitter coupling structure is usually a circular spot with a brighter center and a weak light zone outside. When the size of the collimation beam in the fast axis and slow axis is approximately the same, the far field output uniformity improves greatly. When the angular error of optical fiber along the central axis is large(more than 1°), the uniformity of the output far field spot reduces significantly. For multi-chip fiber coupling, if the step height between single emitters is greater than the size of the collimated beam in the fast axis, the output far field distribution is ring-like with dark zone, and the number of the emitters is corresponding to the number of rings. In order to improve the uniformity of the output far field distribution, the step height between the single emitters must be strictly controlled. © 2017, Science Press. All right reserved.
