Fig. 1. Panda-shaped PCF preform: (a) panda-shaped PCF thin preform, (b) after the first drawing.

Fig. 2. End view of orange petal-shaped PCF in preparation process: (a) cladding pores appear as a whole, (b) crescent gap disappears, (c) orange petal-shaped pores appear, (d) orange petal-shaped PCF.

Fig. 3. End view of panda-shaped PCF in preparation process: (a) cladding pores appear as a whole, (b) crescent gap disappears, (c) panda-shaped PCF integral end face, (d) panda-shaped PCF local amplification.

Fig. 4. Fitting curves of (a) temperature parameters and (b) air pressure parameters with fiber diameter during the preparation of panda-shaped PCF.

Fig. 5. Fitting curves of (a) rod feeding speed and (b) pulling speed with fiber diameter during the preparation of panda-shaped PCF.

Fig. 6. Silver-filled panda-shaped PCF preform: (a) shooting without flash, (b) shooting with flash, (c) thin preform after the first drawing, (d) local enlargement of thin preform.

Fig. 7. End face in the process of drawing silver-filled panda-shaped PCF: (a) pores appear as a whole, (b) crescent gap disappears, (c) squeezed silver wire, (d) silver wire supports large pore, (e) silver-filled panda-shaped PCF integral end face, (f) silver-filled panda-shaped PCF local amplification.

Fig. 8. Fitting curves of (a) temperature parameters and (b) air pressure parameters with fiber diameter during the preparation of silver-filled panda-shaped PCF.

Fig. 9. Fitting curves of (a) rod feeding speed and (b) pulling speed with fiber diameter during the preparation of silver-filled panda-shaped PCF.

Fig. 10. (a) Silver-filled panda-shaped PCF test experiment and (b) contrast spectrum with or without silver wire.