Significant improvement of durability for repeated plugging in and out by ballpoint-pen interconnect of graded-index plastic optical fiber

We investigate influence of repeated plugging in and out processes on data transmission quality through ballpoint-pen interconnect where ball lens can be precisely mounted on graded-index plastic optical fiber (GI POF) end-face using ballpoint-pen production technology. By using the ballpoint-pen interconnect, data transmission quality is barely degraded with repeated plugging in and out, resulting in its better transmission after 2500 cycles of plugging in and out without any cleanings than butt-coupling. This is because coupling loss increment due to dusts and scratches caused by plugging in and out are suppressed owing to protected GI POF end-face from dusts and scratches by ball lens and increased ratio of dusts and scratches to beam width.