Fig. 1. Schematic of energy level structure of Tm³⁺∶YAG crystal

Fig. 2. Flowchart of numerical analysis and solution of RF signal based on Tm³⁺∶YAG crystal

Fig. 3. Power spectrum of an RF signal with a center frequency range of 20 MHz passes through the absorption spectrum of Tm³⁺∶YAG crystal

Fig. 4. Variation of sampling points and spectral resolution with crystal homogeneous broadening

Fig. 5. Variation of sampling points and spectral resolution with the intensity of the written signal

Fig. 6. Power spectrum when reading a 300 kHz spectral hole with different chirp rates

Fig. 7. Variation of sampling points and spectral resolution with the chirp rate of the readout signal

Fig. 8. Experimental setup diagram for broadband radio frequency signal processing based on spectral hole burning

Fig. 9. Signal power spectrum at a working temperature of 9 K