Low-Loss Si3N4 TriPleX Optical Waveguides: Technology and Applications Overview

Abstract

An overview of the most recent developments and improvements to the low-loss TriPleX Si 3 N 4 waveguide technology is presented in this paper. The TriPleX platform provides a suite of waveguide geometries (box, double stripe, symmetric single stripe, and asymmetric double stripe) that can be combined to design complex functional circuits, but more important are manufactured in a single monolithic process flow to create a compact photonic integrated circuit. All functionalities of the integrated circuit are constructed using standard basic building blocks, namely straight and bent waveguides, splitters/combiners and couplers, spot size converters, and phase tuning elements. The basic functionalities that have been realized are: ring resonators and Mach-Zehnder interferometer filters, tunable delay elements, and waveguide switches. Combination of these basic functionalities evolves into more complex functions such as higher order filters, beamforming networks,

Ring resonator enhanced mode-hop-free wavelength tuning of an integrated extended-cavity laser

“…The function of the dielectric chip is to provide frequency selective feedback and to increase the effective cavity length with very low loss. The feedback chip is based on a symmetric double-stripe waveguide geometry of two Si3N4 stripes buried in a SiO2 cladding as described by Roeloffzen et al [31]. This single-mode waveguide exhibits a low propagation loss of about 0.1 dB/cm and enables small bending radii down to 100 µm.…”

8×8 reconfigurable quantum photonic processor based on silicon nitride waveguides

“…Finally, we realize high-dimensional single-photon quantum gates exploiting the whole spatial mode structure of the processor. The photonic processor is based on stoichiometric silicon nitride waveguides, grown with low-pressure chemical vapor deposition, with a double-stripe cross-section [33]. The waveguides exhibit a propagation loss of 0.2 dB/cm for a total on-chip transmission greater than or equal to 60%, a value that corresponds to the longest optical path.…”

Integrated microwave photonics for 5G

“…This, however, is very challenging to achieve using only electronics. For this reason, the last few years, an increasing amount of R&D has been directed to integrated optical beamforming on our low loss Si3N4 TriPleX waveguide platform [2].…”