Study on coupling characteristics of spade fiber and laser diode

A novel technique that a high power laser diode is directly coupled to a spade micro-lens multimode fiber was presented to improve the fiber coupling efficiency and alignment tolerance.With the field matching technology,the relationship of coupling efficiency was deduced.The alignment tolerances for axis and obliquity were also discussed.The coupling efficiency reached up to 78.5% in experiments.It is helpful to improve the practicality of spade fiber coupling systems.