Fig. 1. (a) Scanning electron microscope photographs and normalized plot of the spectrum^[4]; (b) Scanning electron microscope photograph and fiber loss spectrum^[5-6]

Fig. 2. Scanning electron microscope photograph and fiber loss spectrum^[8]

Fig. 3. (a) Scanning electron microscope photograph and (b) fiber loss spectrum^[10]: Experimentally measured transmission loss (red line), simulated fundamental mode transmission loss (orange line)

Fig. 4. (a) Scanning electron microscope photograph; (b) Fiber loss spectrum^[2]

Fig. 5. (a) Transmission and loss spectra; (b) Transmission spectra for different bending-diameters; (c) Bending losses; (d) Scanning electron microscope photograph^[11]

Fig. 6. (a) Scanning electron microscope photograph; (b) Finite element method simulation of the fiber confinement loss; (d) Transmission spectra; (c), (e) Bending loss spectrum^[14]

Fig. 7. Confinement loss spectra and absorption loss spectra. (a) The purple line is the Heraeus F300 silica glass loss spectrum; the blue and black overlapping lines are the absorption loss spectra of NANF and Single-ring, and the red and green lines are the Single-ring and NANF confinement loss spectra, respectively; (b) The total loss spectra of Single-ring and NANF