High-power laser diode arrays are difficult to use directly in such fields as military

industry

and medicine because of their extremely asymmetric divergent beams (θ

x

≈5～10°and θ

y

≈20°～35°)

i.e.

their poor beam quality. In order to improve the beam quality of laser diode arrays

special optical systems have to be used to reshape the asymmetric divergent beams. One most simple and effective beam-reshaping way is to change linearly arranged laser beams of the one-dimension laser diode array (LD Bar) into circularly arranged laser beams by fiber arrays. With flat-end fiber arrays

the coupling efficiency is usually about 20%

which is obviously too low to use in most situations. So

fiber arrays with special ends have to be prepared to obtain both high coupling efficiency and high beam quality output of LD Bar. By ray tracing method

theoretically studied that the coupling properties of three kinds of specially prepared fiber arrays with LD Bar were theoritically studied. The results show that

compared with the sphereend fiber and the tapered fiber

the sphere-end tapered fiber having much higher coupling efficiency (over 90%) with LD Bar was optimized. Moreover

when the sphere-end tapered fiber array is in use

output beams of LD Bar with much higher quality can be obtained due to the strong suppression of divergent angles. The sphere-end tapered fibers are easily prepared in experiment by methods of high-temperature melting and chemical erosion.