Analysis of Optical and Electrical Tradeoffs of Traveling-Wave Depletion-Type Si Mach–Zehnder Modulators for High-Speed Operation

Abstract

Fundamental limiting factors regarding high-speed performance of broadband depletion-type silicon (Si) Mach-Zehnder modulators (MZMs) are studied. Optical and electrical measurements of MZMs with traveling wave electrodes (TWE) reveal significant dependences between optoelectrical bandwidth and design parameters. An equivalent circuit model is implemented to fit measured modulator characteristics. Using the model, the limits of TWE depletion-type Si MZM systems are studied under the requirement of specific driving voltage. By comparing phase shifters with different doping concentration or junction position, we explore the fundamental optical and electrical tradeoffs which are limiting high-speed operation.

A BaTiO3-Based Electro-Optic Pockels Modulator Monolithically Integrated on an Advanced Silicon Photonics Platform

“…Besides a rather low modulation efficiency, nonlinearity and high-loss also limit modulator performance. The impossibility of disentangling amplitude and phase modulation also restricts their use for higher modulation formats [2], [3]. In addition, the high junction capacitance limits the achievable bandwidth [3] and is detrimental for power consumption.…”

“…The impossibility of disentangling amplitude and phase modulation also restricts their use for higher modulation formats [2], [3]. In addition, the high junction capacitance limits the achievable bandwidth [3] and is detrimental for power consumption. It is therefore highly desirable to enable -in a silicon photonic technologypure electro-optic phase shifters exploiting the Pockels effect, in order to provide a solution without residual amplitude modulation, yet with high linearity, high efficiency and low optical loss.…”

Partial Pre-Emphasis for Pluggable 400 G Short-Reach Coherent Systems

“…Silicon photonic traveling wave modulators (TWMZMs) have been actively studied and show good potential for coherent applications [2][3][4][5][6][7][8][9]. To meet the low power requirements in 400 G SiPh coherent systems, short TWMZMs with low V π are attractive, which allow for low-power radio frequency (RF) driver amplifiers (DA).…”

“…To meet the low power requirements in 400 G SiPh coherent systems, short TWMZMs with low V π are attractive, which allow for low-power radio frequency (RF) driver amplifiers (DA). However, this is obtained by trading off the modulator E-O bandwidth, which leads to the transmitter (Tx) low-pass filtering that is significantly stronger than the receiver (Rx) [8]. Furthermore, this is aggravated by the cascaded low-pass frequency response of the arbitrary waveform generator (AWG), which often possesses a comparably low bandwidth in the entire channel.…”

Fast Optimization of Integrated Photonic Components Using Response Correction and Local Approximation Surrogates

“…One of the simplest, yet fundamental types, of integrated photonic components are directional couplers. Coupler structures have numerous applications in, among others, Mach-Zehnder interferometers (Doerr et al 2005;Petousi et al 2015), filters (Yu et al 2011;Zhang and Pan 2013), and switches (de Valicourt et al 2014;Krishnamurthy et al 2014).…”