title: Low V(π) Silicon photonics modulators with highly linear epitaxially grown phase shifters.
abstract: We report on the design of Silicon Mach-Zehnder carrier depletion modulators relying on epitaxially grown vertical junction diodes. Unprecedented spatial control over doping profiles resulting from combining local ion implantation with epitaxial overgrowth enables highly linear phase shifters with high modulation efficiency and comparatively low insertion losses. A high average phase shifter efficiency of VπL = 0.74 V⋅cm is reached between 0 V and 2 V reverse bias, while maintaining optical losses at 4.2 dB/mm and the intrinsic RC cutoff frequency at 48 GHz (both at 1 V reverse bias). The fabrication process, the sensitivity to fabrication tolerances, the phase shifter performance and examples of lumped element and travelling wave modulators are modeled in detail. Device linearity is shown to be sufficient to support complex modulation formats such as 16-QAM.
authors.forename: Saeed Sharif
authors.initials: SS
authors.lastname: Azadeh
authors.forename: Florian
authors.initials: F
authors.lastname: Merget
authors.forename: Sebastian
authors.initials: S
authors.lastname: Romero-García
authors.forename: Alvaro
authors.initials: A
authors.lastname: Moscoso-Mártir
authors.forename: Nils
authors.initials: N
authors.lastname: von den Driesch
authors.forename: Juliana
authors.initials: J
authors.lastname: Müller
authors.forename: Siegfried
authors.initials: S
authors.lastname: Mantl
authors.forename: Dan
authors.initials: D
authors.lastname: Buca
authors.forename: Jeremy
authors.initials: J
authors.lastname: Witzens