Adjustment-free long-distributed-cavity laser using small glass ball cat-eye retroreflector

We report an adjustment-free long-distributed-cavity laser using a small high-index glass ball cat-eye retroreflector as the receiver. When the glass ball cat-eye was rotated or off-axis moved, its working characteristics were studied via the single cat-eye structure and the double cat-eyes structure. With the single cat-eye structure and an incident pump power of 4.22 W, the end-pumped Nd: YVO4 laser delivered 985 mW continuous-wave output at a working distance of 2.85 m, whose full rotation angle at half power was ±27°. In addition, with the double cat-eyes structure and the same incident pump power, the laser delivered 385 mW output at a working distance of 1.20 m, which had a full rotation angle of ±19° and a transverse displacement tolerance of ±21 mm. As far as we know, this is the first time that a ball-shaped cat-eye retroreflector is used to establish an adjustment-free long-distributed-cavity laser.