High-speed low-chirp PAM-4 transmission based on push-pull silicon photonic microring modulators.

Rui Li,Zhenping Xing,David V Plant,Eslam El-Fiky,Mohamed Morsy-Osman,Alireza Samani,David Patel

doi:10.1364/oe.25.013222

Abstract

We report a silicon photonic modulator based on the use of dual parallel microring modulators (MRMs) inserted in a Mach-Zehnder interferometer (MZI). It is operated in a push-pull configuration for low-chirp transmission at approximately 1550 nm. The chirp parameters of the device are measured using 10 Gb/s on-off keying (OOK) transmission over 20 km of standard single mode fiber (SSMF), and they are less than 0.01, showing the low-chirp characteristic of the modulator. We further demonstrate four-level pulse amplitude modulation (PAM-4) transmission at 92 Gb/s over 1 km of SSMF and at 40 Gb/s over 20 km of SSMF. The measured bit error rates (BERs) are below the hard-decision (HD) forward error correction (FEC) threshold of 3.8 × 10-3.

Highlights

From small scale micro-processors in mobile phones and laptops, to large-scale data centers, ultra-high speed data transmission at low cost is becoming an urgent need
We report a silicon photonic modulator based on the use of dual parallel microring modulators (MRMs) inserted in a Mach-Zehnder interferometer (MZI)
We further demonstrate four-level pulse amplitude modulation (PAM-4) transmission at 92 Gb/s over 1 km of standard single mode fiber (SSMF) and at 40 Gb/s over 20 km of SSMF

Summary

Introduction

From small scale micro-processors in mobile phones and laptops, to large-scale data centers, ultra-high speed data transmission at low cost is becoming an urgent need. When the four levels of differential RF data applied on the two MRMs, the transmitted powers of the device at the operating wavelength λ are 0.033, 0.173, 0.327 and 0.477, respectively. They have nearly even spacing, which is reasonable for generating PAM-4 optical signals. Compared to previously reported α-parameters of push-pull MZMs [25,26,27,28], the measured chirp parameters of the device from back-to-back (B2B) to 20 km of SSMF transmission are all very small This shows that the push-pull operation of the dual parallel MRMs is capable of low-chirp modulation

PAM-4 transmission

Conclusion