(a) diagram of the wedged Nd:YVO₄ crystals (The large faces of the crystals are unpolished. The end faces 1, 2, the wedge faces 1, 2, and the side face 2 are polished); (b) Diagram of the fluorescent signal received by SMF (polarizer is omitted to be convenient); (c) the exiting surfaces corresponding to fluorescent emissions of different propagating directions.