Ultra-low loss waveguide platform and its integration with silicon photonics

Abstract

Planar waveguides with ultra-low optical propagation loss enable a plethora of passive photonic integrated circuits, such as splitters and combiners, filters, delay lines, and components for advanced modulation formats. An overview is presented of the status of the field of ultra-low loss waveguides and circuits, including the design, the trade-off between bend radius and loss, and fabrication rationale. The characterization methods to accurately measure such waveguides are discussed. Some typical examples of device and circuit applications are presented. An even wider range of applications becomes possible with the integration of active devices, such as lasers, amplifiers, modulators and photodetectors, on such an ultra-low loss waveguide platform. A summary of efforts to integrate silicon nitride and silica-based low-loss waveguides with silicon and III/V based photonics, either hybridly or heterogeneously, will be presented. The approach to combine these integration technologies heterogeneously on a single silicon substrate is discussed and an application example of a highbandwidth receiver is shown.

TriPleX: a versatile dielectric photonic platform

“…In return, active functionality (light generation, detection, and modulation) available on those platforms is efficiently joined with the TriPleX circuitry. Various complementary functionalities such as high-Q resonators, arrayed waveguide gratings, tunable delay lines, and devices for polarization control available in the ultralow loss silicon nitride waveguide technology and in silicon photonics are reviewed [55,56]. On the SOI side among others, modules based on hybrid integration with the III-V InP technology and magneto-optical materials add to the functionality portfolio.…”

“…A range of TriPleXbased photonic functions and building blocks applicable in telecommunication components including integration with the III-V or silicon platforms was recently investigated by researchers of UCSB [55].…”

Widely-Tunable Ring-Resonator Semiconductor Lasers

“…To improve long-term stability of a semiconductor laser, locking to stable high-Q resonators is typically employed. A demonstration of locking a ring based widely-tunable semiconductor laser to a high-Q resonator made in SiN has shown significant reduction of low-frequency noise [24], and such resonators can be integrated on the same chip [25]. Laser locking to the external resonator lies outside the scope of the paper, but shows potential for extremely stable chip-scale laser, especially as SiN has lower thermo-optic coefficient than Si.…”

Design and characterization of arrayed waveguide gratings using ultra-low loss Si3N4 waveguides

“…Due to their thin and wide core geometries, these ULL Si 3 N 4 waveguides have favorably low propagation loss over a large range of minimum bend radii extending from 20 lm to 7.5 mm (depending on the core thickness) [3]. Furthermore, the recent integration of active hybrid silicon devices [4] makes ULL Si 3 N 4 components promising for the integration of optoelectronic systems requiring long propagation lengths, such as those typically achieved in single-mode fiber [3].…”

“…Furthermore, the recent integration of active hybrid silicon devices [4] makes ULL Si 3 N 4 components promising for the integration of optoelectronic systems requiring long propagation lengths, such as those typically achieved in single-mode fiber [3]. Though previous papers focused on the favorable amplitude characteristic of the waveguides, many target applications also require a good phase characteristic, such that the accumulation of phase errors with propagation in the waveguide is minimal [5].…”