Xiaoke Ruan

Single Carrier 400G Transmission With Single-Ended Heterodyne Detection

We demonstrate single channel 448 Gb/s (56 GBaud) and wavelength division multiplexed (WDM) 1.792-Tb/s transmission of Nyquist polarization division multiplexed 16-ary quadrature amplitude modulation (16-QAM) signal by employing heterodyne detection with single-ended photodiodes. The signal-signal beat interference induced by square-law detection of the single-ended photodiodes is overcome by the Kramers-Kronig scheme. For both single channel 160-km standard single mode fiber (SSMF) transmission and WDM 80-km SSMF transmission, the bit-error rates are below the 7% hard-decision forward error correction threshold of

49.6 Gb/s direct detection DMT transmission over 40 km single mode fibre using an electrically packaged silicon photonic modulator

4.5\times 10^{-3}

Experimental comparison of direct detection Nyquist SSB transmission based on silicon dual-drive and IQ Mach-Zehnder modulators with electrical packaging

. To the best of our knowledge, this letter is the first experiment of single carrier 400G optical transport with heterodyne detection. For WDM operation of high symbol rate heterodyne system, a record net spectral efficiency of 5.71 b/s/Hz is achieved.

Beyond 200G Direct Detection Transmission With Nyquist Asymmetric Twin-SSB Signal at C-Band

We present the characterization of a silicon Mach-Zehnder modulator with electrical packaging and show that it exhibits a large third-order intermodulation spurious-free dynamic range (> 100 dB Hz2/3). This characteristic renders the modulator particularly suitable for the generation of high spectral efficiency discrete multi-tone signals and we experimentally demonstrate a single-channel, direct detection transmission system operating at 49.6 Gb/s, exhibiting a baseband spectral efficiency of 5 b/s/Hz. Successful transmission is demonstrated over various lengths of single mode fibre up to 40 km, without the need of any amplification or dispersion compensation.

16×112Gb/s Single-Sideband PAM4 WDM Transmission over 80km SSMF with Kramers-Kronig Receiver

We have designed and fabricated a silicon photonic in-phase-quadrature (IQ) modulator based on a nested dual-drive Mach-Zehnder structure incorporating electrical packaging. We have assessed its use for generating Nyquist-shaped single sideband (SSB) signals by operating it either as an IQ Mach-Zehnder modulator (IQ-MZM) or using just a single branch of the dual-drive Mach-Zehnder modulator (DD-MZM). The impact of electrical packaging on the modulator bandwidth is also analyzed. We demonstrate 40 Gb/s (10Gbaud) 16-ary quadrature amplitude modulation (16-QAM) Nyquist-shaped SSB transmission over 160 km standard single mode fiber (SSMF). Without using any chromatic dispersion compensation, the bit error rates (BERs) of 5.4 × 10-4 and 9.0 × 10-5 were measured for the DD-MZM and IQ-MZM, respectively, far below the 7% hard-decision forward error correction threshold. The performance difference between IQ-MZM and DD-MZM is most likely due to the non-ideal electrical packaging. Our work is the first experimental comparison between silicon IQ-MZM and silicon DD-MZM in generating SSB signals. We also demonstrate 50 Gb/s (12.5Gbaud) 16-QAM Nyquist-shaped SSB transmission over 320 km SSMF with a BER of 2.7 × 10-3. Both the silicon IQ-MZM and the DD-MZM show potential for optical transmission at metro scale and for data center interconnection.