Manuel Kohli, Daniel Chelladurai, Laurenz Kulmer, Tobias Blatter, Yannik Horst, Killian Keller, Michael Doderer, Joel Winiger, David Moor, Andreas Messner, Tatiana Buriakova, Clarissa Convertino, Felix Eltes, Yuriy Fedoryshyn, Ueli Koch, Juerg Leuthold
An integrated photonics platform that offers high-speed modulators in addition to low-loss and versatile passive components is highly sought after for different applications ranging from AI to next-generation Tbit/s links in optical fiber communication. For this purpose, we introduce the plasmonic BTO-on-SiN platform for high-speed electro-optic modulators. This platform combines the advantages provided by low-loss silicon nitride (SiN) photonics with the highly nonlinear barium titanate (BTO) as the active material. Nanoscale plasmonics enables high-speed modulators operating at electro-optical bandwidths up to 110 GHz with active lengths as short as 5 µm. Here, we demonstrate three different modulators: a 256 GBd C-band Mach-Zehnder (MZ) modulator, a 224 GBd C-band IQ modulator - being both the first BTO IQ and the first IQ modulator on SiN for data communication - and finally, a 200 GBd O-band racetrack (RT) modulator. With this approach we show record data rates of 448 Gbit/s with the IQ modulator and 340 Gbit/s with the MZ modulator. Furthermore, we demonstrate the first plasmonic RT modulator with BTO and how it is ideally suited for low complexity communication in the O-band with low device loss of 2 dB. This work leverages the SiN platform and shows the potential of this technology to serve as a solution to combat the ever-increasing demand for fast modulators.