Figure 1: The fabrication and fluorescence characteristic of superficial cladding waveguides.

(a) Schematic of experimental arrangement for the passively Q-switched laser operation in Nd:YVO₄ superficial cladding waveguide. The insert is the microscope image of the laser-written waveguide. (b) Room-temperature fluorescence emission spectra (μPL) related to the ⁴F_3/2 → ⁴I_9/2 and ⁴F_3/2 → ⁴I_11/2 transitions of Nd³⁺ ions obtained from the laser inscribed waveguide volume (red solid line) and bulk region (blue solid line) of Nd:YVO₄ crystal. The insert in (b) shows the 2D spatial distribution of the emitted intensity of Nd³⁺ emission line obtained from the end-face of waveguide, which corresponds to the region within the red dashed square in the microscope image (i.e., the insert of a).