[1] Carena A, Curri V, Poggiolini P et al. Maximum reach versus transmission capacity for terabit superchannels based on 27.75-GBaud PM-QPSK, PM-8QAM, or PM-16QAM[J]. IEEE Photonics Technology Letters, 22, 829-831(2010).

[2] Wang X L. Influence of transceiver noise on nonlinearity-compensated optical transmission systems[J]. Laser & Optoelectronics Progress, 58, 2306010(2021).

[3] Mamyshev P V. All-optical data regeneration based on self-phase modulation effect[C], 475-476(1998).

[4] Kong X J, Wu B J, Zhou X Y et al. Design of all-optical multi-level regenerators based on Mach-Zehnder interferometer[J]. Optics Communications, 380, 377-381(2016).

[5] Bottrill K R H, Kakarla R, Parmigiani F et al. Phase regeneration of QPSK signal in SOA using single-stage, wavelength converting PSA[J]. IEEE Photonics Technology Letters, 28, 205-208(2016).

[6] Wen F, Tsekrekos C P, Geng Y et al. All-optical multilevel amplitude regeneration in a single nonlinear optical loop mirror[J]. Optics Express, 26, 12698-12706(2018).

[7] Lu H, Wu B J, Wan F et al. Research on dynamic transfer characteristics of clock-pumped fiber regenerators[J]. Laser & Optoelectronics Progress, 55, 090603(2018).

[8] Perentos A, Fabbri S, Sorokina M et al. QPSK 3R regenerator using a phase sensitive amplifier[J]. Optics Express, 24, 16649-16658(2016).

[9] Jiang S L, Wu B J, Sun F et al. Reshaping characteristics of multilevel all-optical amplitude regenerators[J]. Laser & Optoelectronics Progress, 54, 052303(2017).

[10] Slavík R, Parmigiani F, Kakande J et al. All-optical phase and amplitude regenerator for next-generation telecommunications systems[J]. Nature Photonics, 4, 690-695(2010).

[11] Sorokina M. Design of multilevel amplitude regenerative system[J]. Optics Letters, 39, 2499-2502(2014).

[12] Dong Y, Zhao S H, Li Y J et al. Wavelength-shift-free optical regeneration on satellite using cascading SOA with two-stage offset filter[J]. Acta Optica Sinica, 35, 0506008(2015).

[13] Roethlingshoefer T, Richter T, Schubert C et al. All-optical phase-preserving multilevel amplitude regeneration[J]. Optics Express, 22, 27077-27085(2014).

[14] Lali-Dastjerdi Z, Galili M, Mulvad H C H et al. Parametric amplification and phase preserving amplitude regeneration of a 640 Gbit/s RZ-DPSK signal[J]. Optics Express, 21, 25944-25953(2013).

[15] Lakoba T I, Vasilyev M. On multi-channel operation of phase-preserving 2R amplitude regenerator[J]. Optics Communications, 322, 114-117(2014).

[16] Roethlingshoefer T, Onishchukov G, Schmauss B et al. Cascaded phase-preserving multilevel amplitude regeneration[J]. Optics Express, 22, 31729-31734(2014).

[17] Guo B, Wu B J, Wang Y X et al. On-chip Mach Zehnder interferometer-based all-optical amplitude regenerator for optical 16-QAM signals[J]. Optics Express, 29, 27683-27695(2021).

[18] Wen F, Wu B J, Qiu K et al. Conjugate nonlinear-optical loop mirror (Conj-NOLM)-based phase-preserving multilevel amplitude regenerator[J]. Optics Express, 27, 19940-19949(2019).

[19] Meng T H, Yu J L, Wang J et al. 2 × 40 Gb/s all-optical 3R regeneration system using four-wave mixing in dispersion shifted fiber[J]. Acta Optica Sinica, 32, 0806004(2012).

[20] Chen J M, Guo X J. Widely tunable mid-infrared spectral translation in chalcogenide waveguide with normal dispersion[J]. Laser & Optoelectronics Progress, 59, 0323003(2022).

[21] Zhang D M, Jiang Z F. Dynamics of semiconductor ring laser subject to phase conjugate optical feedback[J]. Laser & Optoelectronics Progress, 58, 1919001(2021).

[22] Guo B, Wu B J, Wen F et al. All-optical phase-preserving amplitude regeneration of highorder modulated signals based on Mach-Zehnder interferometers[C], JW4A.11(2019).

[23] Zhang S Q, Wu B J, Sun F et al. Optimization method for universal NOLM-based phase-preserving amplitude regenerator with application to Att-NALM scheme[J]. Optics Communications, 475, 126188(2020).

[24] Guo B, Wu B J, Wen F et al. Phase-preserving principle of all-optical regenerators with applications to MZI-nested NOLM structure[J]. Optics Express, 30, 20175-20184(2022).

[25] Gordon J P, Mollenauer L F. Phase noise in photonic communications systems using linear amplifiers[J]. Optics Letters, 15, 1351-1353(1990).

[26] Guo B, Wen F, Wu B J et al. All-optical multilevel amplitude regeneration based on polarization-orthogonal continuous-wave-light-assisted nonlinear-optical loop mirror (PC-NOLM) subsystem[J]. IEEE Access, 7, 149666-149671(2019).

[27] Pottiez O, Ibarra-Escamilla B, Kuzin E A. Large amplitude noise reduction in ultrashort pulse trains using a power-symmetric nonlinear optical loop mirror[J]. Optics & Laser Technology, 41, 384-391(2009).

[28] Sorokina M, Sygletos S, Ellis A et al. Regenerative Fourier transformation for dual-quadrature regeneration of multilevel rectangular QAM[J]. Optics Letters, 40, 3117-3120(2015).