Research on coupling efficiencies of ball lenses

The coupling efficiencies of the ball lenses used in coupling of the laser diode(LD) and single mode fiber(SMF) were calculated and researched by a energy integration method.Research results indicate that when the single ball lens is used in the LD-ball lens-SMF system,the axial alignment tolerance is ±30 μm,the lateral alignment tolerance is ±1.0 μm and the tilting on the X-Y plane pivoting at the fiber tip is ±1.2°.When the double ball lenses are used in the LD-ball lenses-SMF system,the coupling loss of the tilting tolerance is maximum,the coupling loss of the lateral alignment tolerance is smaller than that of the tilting tolerance and the coupling loss of the axial alignment tolerance is minimum.