Fig. 1. TEM images and size distribution of PbS QDs. (a) TEM image of PbS QDs (20 nm scale); (b) TEM image of PbS QDs (5 nm scale); (c) size distribution of PbS QDs

Fig. 2. Cross-sectional diagram of PCF (provided by NKT Photonics, Denmark)

Fig. 3. QD-PCF contrast before and after volatilization of quantum dot solution. (a) QD-PCF filled with quantum dot solution; (b) QD-PCF after volatilization of solution

Fig. 4. Measured PL emission and absorption spectra of PbS QDs

Fig. 5. Measured optical power of QD-PCF varying with fiber length. (a) 980 nm pump light power; (b) 1550 nm signal light power

Fig. 6. PL-peak intensity of QD-PCF varying with fiber length for different doping concentrations

Fig. 7. PL spectra of QD-PCF and QDF. (a) PL spectra of QD-PCF; (b) comparison of PL spectra between QD-PCF and QDF

Fig. 8. Measured bandgap of QD-PCF (for 6.5 cm fiber length and 5 mg·mL-1 doping concentration)

Fig. 9. PL-peak intensity of QD-PCF varying with pump power