Fig. 1. Schematic of the sample fabrication. (a) Pure Nd:YAG. (b) Cu+ ions implantation. (c) C4+ ions irradiation. (d) Diamond blade slicing.

Fig. 2. (a) TEM image of the sample and projection distribution of implanted Cu+ ions. (b) Cu element distribution mapping. (c) HRTEM image. (d) Diameter distribution of NPs.

Fig. 3. (a) Measured linear optical absorption spectrum. Insert is the picture of the sample. (b) Calculated linear optical absorption spectrum.

Fig. 4. (a) Schematic of OA Z-scan system. (b) The nonlinear optical response of samples under the excitation of 340 fs pulses at 1030 nm.

Fig. 5. (a) Schematic of evanescent field coupling effect. (b) Near-field distribution of the sample without Cu NPs. (c) Near-field distribution of the sample with Cu NPs.

Fig. 6. (a) Output power as a function of the launched power. (b) The emission spectrum of the output waveguide laser. Inset is the near-field modal profile. (c) Single Q-switched envelope on the nanosecond time scale under the launched power of 450 mW. (d) Measured mode-locked pulse train.