Fig. 1. Testing scheme for the performance of FPE calibrator

Fig. 2. The spectrum of FPE calibrator measured by HRS

Fig. 3. The measured FSR of FPE by HRS

Fig. 4. Profiles of thorium lines measured by HRS， super-Gaussian fitting curves of the measured thorium lines， and the FPE theoretical transmission spectral lines

Fig. 5. Profiles of Simulated and measured FPE spectral lines

Fig. 6. The temperature monitoring data of FPE calibrator， the shadow areas are the periods of LFC-FPE testing

Fig. 7. The drifting performance of FPE calibrator

Fig. 8. Histograms of residuals between the wavelengths of spectral lines and the wavelengths calculated by corresponding wavelength solutions

Fig. 9. Histogram of residuals between the locked wavelengths of LFC spectral lines and the wavelengths calculated by ThAr and FPE wavelength solutions