Fig. 1. (a) Schematic diagram of the seven-core fiber; (b) schematic of the MZI filter based on tapered seven-core fiber.

Fig. 2. Transmission spectra of the MZI with different FSRs.

Fig. 3. Schematic diagram of the wavelength-tunable mode-locked fiber laser.

Fig. 4. Characteristics of the dissipative solitons. (a) Optical spectrum; (b) pulse train; (c) autocorrelation trace; (d) RF spectrum.

Fig. 5. Tunable results of the dissipative solitons. (a) Optical spectra; (b) variations of 10 dB bandwidth and pulse duration versus the central wavelength; (c) variations of the pulse energy versus the central wavelength.

Fig. 6. Switchable dual-wavelength dissipative solitons. (a) Transmission spectrum of MZI filter with an FSR of 23.8 nm; (b), (c) optical spectra; (d), (e) pulse trains; (f), (g) autocorrelation traces; (h), (i) RF spectra.

Fig. 7. Characteristics of the amplifier similaritons. (a) Optical spectrum; (b) wide-band RF spectrum up to 300 MHz with a resolution of 100 Hz (inset, the narrow bandwidth RF spectrum from 15.5 to 35.5 MHz).

Fig. 8. Tunable results of the amplifier similaritons. (a) Optical spectra; (b) variations of 10 dB bandwidth and pulse duration versus central wavelength; (c) variations of pulse energy versus central wavelength.