Ultra-low-loss high-aspect-ratio Si_3N_4 waveguides

Abstract

We characterize an approach to make ultra-low-loss waveguides using stable and reproducible stoichiometric Si3N4 deposited with low-pressure chemical vapor deposition. Using a high-aspect-ratio core geometry, record low losses of 8-9 dB/m for a 0.5 mm bend radius down to 3 dB/m for a 2 mm bend radius are measured with ring resonator and optical frequency domain reflectometry techniques. From a waveguide loss model that agrees well with experimental results, we project that 0.1 dB/m total propagation loss is achievable at a 7 mm bend radius with this approach.

Harnessing mode-selective nonlinear optics for on-chip multi-channel all-optical signal processing

“…The design of the MSND can be implemented using other nonlinear materials/platforms, e.g., silicon nitride 34,35 or chalcogenide. 15 For example, silicon nitride offers small propagation loss (on the order of 0.03 dB/cm 35 ), relatively large nonlinearity, and negligible nonlinear loss.…”

“…15 For example, silicon nitride offers small propagation loss (on the order of 0.03 dB/cm 35 ), relatively large nonlinearity, and negligible nonlinear loss. Moreover, apart from nonlinear optical signal processing, the MSND can potentially be used in microwave photonics applications, and in particular, where nonlinear optics is used for microwave signal processing, such as XPM-based radio-frequency spectrum analysis 36 and FWM-based instantaneous frequency measurements.…”

Integrated Microwave Photonics for Wideband Signal Processing

“…Thanks to the CMOS-compatible fabrication technology which promises a more cost effective, robust and compact solution, delay elements based on various chip-scale platforms have been intensively investigated. In particular, low propagation loss has been demonstrated in optical waveguides of wedge geometry, high-aspect-ratio Si3N4, and high-quality silicon oxynitride films [32][33][34][35][36]. In [32], an optical delay line fabricated on a silicon chip has been presented, exhibiting an average measured waveguide loss of 0.08 ± 0.01 dB/m in long spirals.…”

Sideband pump-probe technique resolves nonlinear modulation response of PbS/CdS quantum dots on a silicon nitride waveguide

“…29 Silicon nitride (Si 3 N 4 ) can be manufactured into high quality low-loss waveguides and resonators. [30][31][32] Additionally, a range of hybrid photonic devices based on silicon nitride structures has been demonstrated. 10,[33][34][35][36][37] In contrast to pure silicon, the material does not display large intrinsic nonlinearities or a substantial free carrier absorption 38 and therefore allows us to observe the nonlinear response of the QDs without waveguide-induced background.…”