800 Gbit/s transmission over 1 km single-mode fiber using a four-channel silicon photonic transmitter
Hongguang Zhang, Miaofeng Li, Yuguang Zhang, Di Zhang, Qiwen Liao, Jian He, Shenglei Hu, Bo Zhang, Lei Wang, Xi Xiao, N. D. Qi, Shaohua Yu
Abstract
We demonstrate the optical transmission of an 800 Gbit/s ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"> <mml:mrow> <mml:mn>4</mml:mn> <mml:mo>×</mml:mo> <mml:mn>200</mml:mn> <mml:mtext> </mml:mtext> <mml:mi>Gbit</mml:mi> <mml:mo>/</mml:mo> <mml:mi mathvariant="normal">s</mml:mi> </mml:mrow> </mml:math> ) pulse amplitude modulation-4 (PAM-4) signal and a 480 Gbit/s ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m2"> <mml:mrow> <mml:mn>4</mml:mn> <mml:mo>×</mml:mo> <mml:mn>120</mml:mn> <mml:mtext> </mml:mtext> <mml:mi>Gbit</mml:mi> <mml:mo>/</mml:mo> <mml:mi mathvariant="normal">s</mml:mi> </mml:mrow> </mml:math> ) on–off-keying (OOK) signal by using a high-bandwidth (BW) silicon photonic (SiP) transmitter with the aid of digital signal processing (DSP). In this transmitter, a four-channel SiP modulator chip is co-packaged with a four-channel driver chip, with a measured 3 dB BW of 40 GHz. DSP is applied in both the transmitter and receiver sides for pre-/post-compensation and bit error rate (BER) calculation. Back-to-back (B2B) BERs of the PAM-4 signal and OOK signal are first measured for each channel of the transmitter with respect to a variety of data rates. Similar BER performance of four channels shows good uniformity of the transmitter between different channels. The BER penalty of the PAM-4 and OOK signals for 500 m and 1 km standard single-mode fiber (SSMF) transmission is then experimentally tested by using one channel of the transmitter. For a 200 Gbit/s PAM-4 signal, the BER is below the hard-decision forward error correction (HD-FEC) threshold for B2B and below the soft-decision FEC (SD-FEC) threshold after 1 km transmission. For a 120 Gbit/s OOK signal, the BER is below SD-FEC threshold for B2B. After 500 m and 1 km transmission, the data rate of the OOK signal shrinks to 119 Gbit/s and 118 Gbit/s with the SD-FEC threshold, respectively. Finally, the 800 Gbit/s PAM-4 signal with 1 km transmission is achieved with the BER of all four channels below the SD-FEC threshold.