Fig. 1. The experimental setup. (a) Cross section of the crystal waveguide; (b) Top view of the crystal waveguide with light passing through; (c) Sketch of the experimental setup FC: fiber coupler; AOM: acousto-optic modulator; HWP: half-wave plate; PBS: polarizing beam splitter; FR: Faraday rotator

Fig. 2. Experimental protocol. (a) Energy levels of the ${{}_{}{}^{\mathrm{7}}}_{\mathrm{0}}\leftrightarrow {{}_{}{}^{\mathrm{5}}\mathrm{D}}_{\mathrm{0}}$ transition of ¹⁵¹Eu³⁺:Y₂SiO₅;(b) Initial state preparation sequence and freqency span of each pulse; (c) SLSE pulse sequense

Fig. 3. Experimental result of SLSE light storage. (a) Histogram of light storage experiment for 1.4 s;(b) Storage efficiency depending on the storage time