Net 220 Gbps/λ IM/DD Transmssion in O-Band and C-Band With Silicon Photonic Traveling-Wave MZM

Abstract

We present the design and characterization of Oband and C-band silicon photonic (SiP) traveling wave Mach-Zehnder modulators (TW-MZM) allowing 220 Gbps/λ net rate operation. The designed modulators show over 45 GHz 3-dB E-O bandwidth with a single-segment design. In the O-band, with simple linear feed forward equalization, we transmit net 203 (200) Gbps signal over 2 km (10 km) of single-mode fiber (SMF) below the hard-decision forward error correction (HD-FEC) BER threshold of 3.8×10 -3 . With the aid of nonlinear Volterra equalizer and one 2.3Vpp driving signal, we transmit net 225 (216) Gbps PAM8 signals assuming 20% overhead soft-decision FEC with a normalized general mutual information (NGMI) threshold of 0.8798 over 2 km (10 km) of SMF. The C-band design enables net 220 Gbps in B2B and net 215 Gbps over 500 m of SMF above the specified NGMI threshold. These results are the highest reported net rate for SiP MZM in an intensity modulation direct-detection (IM/DD) system, fabricated entirely in a commercial foundry. Index Terms-Intensity modulation, electrooptic modulators, optical interconnections, Volterra equalization.3, which is the highest reported rate for a Si MRM. In [12], 200 Gbps PAM6 (net 167 Gbps) signal transmission over 1 km of SMF was achieved at a BER below the 20% HD-FEC threshold of 1.5×10 -2 using a SiP TW-MZM with a 3-dB EO bandwidth

Breaking the bandwidth limit of a high-quality-factor ring modulator based on thin-film lithium niobate

“…However, being a semiconductor device, the operational speed of such modulators is still limited, to some extent, by the carrier dynamics 12 . For example, Si-based modulators with buried PN junctions still exhibit modulation bandwidths up to several tens of GHz 13,14 .…”

“…However, being a semiconductor device, the operational speed of such modulators is still limited, to some extent, by the carrier dynamics 12 . For example, Si-based modulators with buried PN junctions still exhibit modulation bandwidths up to several tens of GHz 13,14 .They often suffer from a high insertion loss due to optical absorptions resulted from the carriers 12,15 .Alternatively, electro-optical (EO) material exhibiting a linear Pockels effect can be used to construct a high-performance modulator potentially 16 . Pockels effect, resulted from the variation of the spontaneous electric polarization by an external electric eld, is nearly instantaneous 17 .…”

Equivalent circuit model of the carrier-depletion-based push-pull silicon optical modulators with T-rail slow wave electrodes

“…Increasing a modulator's bandwidth is most commonly achieved by changing its electrode structure. Two traditional traveling wave electrodes (TWE) are coplanar waveguides (CPW) and coplanar strip lines (CPS) [3][4][5][6]. [7,8].…”

200 Gb/s Optical-Amplifier-Free IM/DD Transmissions Using a Directly Modulated O-Band DFB+R Laser Targeting LR Applications

“…In recent years, many 200 Gb/s/lane IM/DD transmissions have been demonstrated using different types of enabling broadband optoelectronic components [4]. On the one hand, external modulator-based transmitters such as silicon-photonic [5,6], plasmonic [7][8][9], and thin-film Lithium Niobate-(TFLN) [10][11][12][13] Mach-Zehnder modulators (MZM) or micro-ring modulators (MRM) [14][15][16] have shown excellent performance in terms of bandwidth and modulation linearity for high baud rate operation, however, requiring high-power external light sources to operate. On the other hand, monolithically integrated transmitters such as electro-absorption modulated lasers (EML) [17][18][19][20][21][22][23][24][25] and directly modulated lasers (DML) [26][27][28][29][30][31] with a potentially smaller footprint and lower power consumption, also show promising characteristics in supporting over 200 Gb/s/lane transmissions.…”