Fig. 1. Schematic diagram of phase shifted HLPG structure

Fig. 2. Schematic diagram of the experimental setup for HLPG fabrication

Fig. 3. Transmission spectra of strongly modulated HLPG based on different mode conversion. (a) LP₀₁-LP₂₁ mode; (b) LP₀₁-LP₃₁ mode

Fig. 4. Transmission spectra of strongly modulated HLPG with single phase shift. (a) LP₀₁-LP₂₁ mode; (b) LP₀₁-LP₃₁ mode

Fig. 5. Transmission spectra of strongly modulated HLPG with multiple phase shift. (a) LP₀₁-LP₂₁ mode; (b) LP₀₁-LP₃₁ mode

Fig. 6. Schematic diagram of HLPG output mode detection device

Fig. 7. The output mode intensity and interference patterns of the broadband HLPG based on LP₀₁-LP₂₁ mode conversion

Fig. 8. The output mode intensity and interference patterns of the broadband HLPG based on LP₀₁-LP₃₁ mode conversion

Fig. 9. Torsion characteristics of broadband HLPG based on different mode conversion. (a) LP₀₁-LP₂₁ mode; (b) LP₀₁-LP₃₁ mode

Fig. 10. Strain characteristics of broadband HLPG based on different mode conversion. (a) LP₀₁-LP₂₁ mode; (b) LP₀₁-LP₃₁ mode