Fig. 1. Schematic illustrations of high out-of-band suppression ratio FIR MPF using SFBG and Gaussian window function with (a) 24 taps and (b) 18 taps

Fig. 2. Schematic illustration of the high out-of-band suppression ratio FIR MPF using Sagnac loop and Kaiser window function

Fig. 3. (a) Schematic illustration of the high out-of-band suppression ratio FIR MPF using the Gaussian apodized broadband combs; (b) depiction of the cascaded FWM process

Fig. 4. Schematic illustrations of the 3rd IIR MPF based on the interference effect between the compositions of the tap

Fig. 5. Four schematic illustrations of cascade configurations of high order IIR MPF

Fig. 6. Schematic illustrations of high out-of-band suppression ratio single bandpass MPF using subtractive in (a) electric and (b) optical domains

Fig. 7. Schematic illustration of high out-of-band suppression ratio single bandpass MPF using modified subtraction in optical domain

Fig. 8. Schematic illustration of high out-of-band suppression ratio single bandpass MPF using (a) passive Lyot optical filter and (b) active optical SBS gain spectrum filter based on spectrum mapping approaches

Fig. 9. Three schemes of notch MPF and theory of notch depth

Fig. 10. (a) Schematic illustration of on-off between bandpass and notch MPFs; (b) spectral respons of the notch MPF; (c) spectral response of bandpass MPF

Fig. 11. (a) Schematic illustration of a single bandpass MPF based on carrier-suppressed single sideband injected DFB laser and (b) spectral responses under different detuning frequencies