DSP-enabled 50G OOK-PON with beyond 29 dB power budget using O-band 10G DML and 10G APD

In this paper, we experimentally demonstrate a digital signal processing (DSP)-enabled 50G on–off keying passive optical network (PON) using cost-effective O-band 10G directly modulated laser and 10G avalanche photodiode. The bandwidth-limited devices induce serious spectral distortions, leading to an unacceptable performance. Digital pre-distortion at the transmitter and post-detection at the receiver are proposed to jointly compensate the serious spectral distortions. The digital pre-distortion at the transmitter can compensate for a part of spectral distortions, but cannot deal with the fast power fading within the high-frequency range. At the receiver, the digital post-detection is proposed to compensate the high-frequency distortions, which mainly includes the polynomial nonlinear equalizer, two-tap post filter, and maximum likelihood sequence estimation (MLSE) with channel estimator. Different from the conventional digital post-detection, the channel estimator can estimate more accurate channel information for MLSE, leading to a better bit error rate (BER) performance. By using the proposed digital signal processing, power budget beyond 29 dB is achieved at BER of 2×10⁻² after 20 km standard single-mode fiber transmission. In conclusion, the proposed DSP-enabled 50G-PON shows great application potentials for the next-generation PON.