Design, analysis, and transmission system performance of a 41 GHz silicon photonic modulator

Abstract

The design and characterization of a slow-wave series push-pull traveling wave silicon photonic modulator is presented. At 2 V and 4 V reverse bias, the measured -3 dB electro-optic bandwidth of the modulator with an active length of 4 mm are 38 GHz and 41 GHz, respectively. Open eye diagrams are observed up to bitrates of 60 Gbps without any form of signal processing, and up to 70 Gbps with passive signal processing to compensate for the test equipment. With the use of multi-level amplitude modulation formats and digital-signal-processing, the modulator is shown to operate below a hard-decision forward error-correction threshold of 3.8×10^-3 at bitrates up to 112 Gbps over 2 km of single mode optical fiber using PAM-4, and over 5 km of optical fiber with PAM-8. Energy consumed solely by the modulator is also estimated for different modulation cases.

Low-loss high-extinction-ratio single-drive push-pull silicon Michelson interferometric modulator

“…Another one is based on the Mach-Zehnder interferometer (MZI) structure, with a broad optical bandwidth and a high temperature tolerance. The recorded modulation speed is higher than 70 Gb/s [10] . By combining the merits of both MZI and microring resonator structures, a high-speed microring modulator based on coupling modulation has been demonstrated with a low drive voltage and low power consumption [11] .…”

“…The single-drive TWE has an improved modulation bandwidth due to its lower microwave attenuation arising from the reduced capacitance compared to a dual-drive TWE [10,17] . The MIM has a high static ER of more than 30 dB and a low V π ·L π of 0.95-1.26 V·cm.…”

Time-Domain Large-Signal Modeling of Traveling-Wave Modulators on SOI

“…Performance, EO bandwidth and impedance matching may vary due to deviation from these levels during the fabrication process. The presence of the reverse biased p-n-junction can be incorporated into the TML circuit model of a quasi TEM mode by transforming the series RjCj elements into a parallel combination [12,13]. The depletion capacitance and resistance, as shown in Fig.…”

“…The depletion capacitance and resistance, as shown in Fig. 3a, decrease with increasing reverse driving voltage, hence the characteristics of the loaded transmission line also become dependent on the driving voltage [5,10,12].…”

“…Coplanar waveguide (CPW) and coplanar strip (CPS) transmission line (TML) are commonly used as traveling-wave electrodes for high-speed modulators [11][12][13][14][15]. The CPS is considered in this case as our traveling wave electrode because of its compact geometry in comparison to CPW.…”