High coupling optical design for laser diodes with large aspect ratio

We have designed and performed the optical modeling of a cruciform cylindri cal lens to replace the corrective lens in a confocal optical system and de monstrated a coupling efficiency of 85%. This represents more than 3 dB imp rovement over the conventional confocal system of single mode fiber couplin g for 980 nm pump lasers. Also, the fiber alignment tolerance is about thre e times more relaxed than that of the wedged fiber lens.