[1] LU Y P, WANG J P. Digital gap or information welfare: The effect of internet use on individual subjective well-being in China［J］. Economic Perspectives, 2020, 708(2): 61-75(in Chinese).

[2] VEEN D V, HOUTSMA V. Strategies for economical next-generation 50G and 100G passive optical networks ［J］. Journal of Optical Communications and Networking, 2020, 12(1): A95.

[3] WANG X, NIU P, ZHENG Z, et al. Miniature acoustic resonator induced in-situ electrode foul removal enabling the continuous electrochemical measurements［C］//2021 IEEE 34th International Confe-rence on Micro Electro Mechanical Systems. New York, USA: IEEE, 2021: 1019-1022.

[4] LIU X, EFFENBERGER F. Emerging optical access network techno-logies for 5G wireless［J］. Journal of Optical Communications & Networking, 2016, B8(12): 70-79.

[5] XU G Y, HU L F, DENG C R, et al. Construction of dynamic model of semiconductor optical amplifier based on iterative algorithm［J］. Laser Technology, 2020, 44(2): 255-260(in Chinese).

[6] CHEN X R, CHU G Y. Research on optimization of optical network unit of full-duplex direct modulation laser［J］. Laser & Infrared, 2021, 51(7): 865-870(in Chinese).

[7] LIU L X, XU L, WANG Q, et al. Measurement of the chirp parameter in DFB semiconductor laser diode［J］. Journal of Henan Normal University(Natural Science Edition), 2018, 46(6): 34-38(in Chin-ese).

[8] FENG S Ch, FAN Y Y, CHEN X Y, et al. Design of multicarrier optical source using cascaded electro-absorption modulator and phase modulator［J］. Chinese Journal of Lasers, 2016,43(11): 1106001(in Chinese).

[9] BAIER M, GROTE N, MOEHRLE M, et al. Integrated transmitter devices on InP exploiting electro-absorption modulation［J］. PHOTONIX, 2020, 1(1): 1-11.

[10] KOBAYASHI W, FUJISAWA T, ITO T,et al.Advantages of EADFB laser for 25Gbaud/s 4-PAM (50Gbit/s) modulation and 10km single-mode fibre transmission［J］. Electronics Letters, 2014, 50(9): 683-685.

[11] LERIN A, CHU G Y, POLO V, et al. Chip integrated DFB-EAM for directly phase modulation performance improvement in UDWDM-PON［C］//2015 European Conference on Optical Communication (ECOC). New York, USA: IEEE, 2015: 1-3.

[12] CHEN X R, CHU G Y. 10Gbit/s bidirectional transmission with an optimized SOA and a SOA-EAM based ONU［J］. Applied Sciences, 2020, 10(24): 8960.

[13] LIU Zh, LI X L, NIU Ch Q, et al. 56 Gbps high-speed Ge electro-absorption modulator［J］. Photonics Research, 2020, 8(10): 131-135.

[14] EL-HAGEEN H M, KUPPUSAMY P G, ALATWI A M, et al. Di-fferent modulation schemes for direct and external modulators based on various laser sources［J］. Journal of Optical Communications, 2020, 29(15): 1-10.

[15] BANJHAL S, MEHRA R. Design and simulation of reflective modulators based on semiconductor optical amplifier and electro-absorption modulator［C］//2015 International Conference on Computer, Communication and Control (IC4). New York, USA: IEEE, 2015: 1-6.

[16] SHINDO T, FUJIWARA N, KANAZAWA S, et al. High power and high speed soa assisted extended reach EADFB laser (AXEL) for 53Gbaud PAM4 fiber-amplifier-less 60km optical link［J］. Journal of Lightwave Technology, 2020, 38(11): 2984-2991.

[17] REN M Zh, XU T W, ZHANG F X, et al. Statistical properties of rayleigh backscattered light in single-mode fibers caused by a highly coherent laser［J］. Chinese Journal of Lasers, 2013,40(1): 0105001(in Chinese).

[18] TABARES J A, GHASEMI S, POLO V, et al. Simplified carrier recovery for intradyne optical PSK receivers in udWDM-PON［J］. Journal of Lightwave Technology, 2018, 36(14): 2941-2947.

[19] MASATO A, YOSHIDA C, KOSUKE T, et al. Single-channel 15.3 Tbit/s, 64 QAM coherent Nyquist pulse transmission over 150km with a spectral efficiency of 8.3bit/s/Hz［J］. Optics Express, 2019, 27(20): 28952-28967.