Implementation, Modelling and Verification of High-Speed Mach-Zehnder Phase Modulators in an Open Access InP Foundry Platform

We present the introduction of high-speed phase modulators based on the quantum-confined Stark effect to the generic InP foundry platform at Fraunhofer HHI. An overview of the technological integration of the high-speed phase Mach-Zehnder modulators (MZM) to the existing generic foundry process is described. In addition, an electro-optical behavioral model for the high speed MZM, which gives insight into the influence of design parameters on performance, is discussed. The presented MZM structure with a traveling wave electrode length of 5 mm has a $V_\pi$ of 1.4 V and a small signal electro-optic 3 dB bandwidth of 32 GHz. Large signal RF operation up to 80 Gbps is demonstrated. To the best of our knowledge, these are the highest-performance MZMs in an InP open access integrated photonics foundry platform.

I. Introduction

With the increase in demand for streaming services and cloud storage platforms, large-capacity optical fibers are becoming ever more important in short- and middle-reach links, such as those in datacenter networks [1]. Coherent optical transceivers with fast modulators are key in fulfilling this demand and realizing them on an open access integrated platform provides a cost-effective solution. HHI not only has long standing expertise in developing high-speed phase Mach-Zehnder modulators (MZM) [2] but also offers its generic InP foundry process in the form of open access Multi-Project Wafer (MPW) runs via the JePPIX platform [3], [4]. This allows external customers to realize their optical interconnect application specific photonic integrated circuits (PICs) at a low cost and fast turn-around time. The generic foundry already offers DFB lasers with output power of 10 dBm, polarization rotators with polarization extinction ratio more than 16 dB over the entire C-band [5] and high speed photodetectors (PD) with small signal 3 dB bandwidth of 40 GHz [4].