TriPleX: a versatile dielectric photonic platform

Abstract

Photonic applications based on planar waveguide technology impose stringent requirements on properties such as optical propagation losses, light coupling to optical fibers, integration density, as well as on reliability and reproducibility. The latter is correlated to a high level of control of the refractive index and waveguide geometry. In this paper, we review a versatile dielectric waveguide platform, called TriPleX, which is based on alternating silicon nitride and silicon dioxide films. Fabrication with CMOS-compatible equipment based on low-pressure chemical vapor deposition enables the realization of stable material compositions being a prerequisite to the control of waveguide properties and modal shape. The transparency window of both materials allows for the realization of low-loss waveguides over a wide wavelength range (400 nm-2.35 μm). Propagation losses as low as 5 × 10 -4 dB/cm are reported. Three basic geometries (box shell, double stripe, and filled box) can be distinguished. A specific tapering technology is developed for on-chip, low-loss ( < 0.1 dB) spotsize convertors, allowing for combining efficient fiber to chip coupling with high-contrast waveguides required for increased functional complexity as well as for hybrid integration with other photonic platforms such as InP and SOI. The functionality of the TriPleX platform is captured by verified basic building blocks. The corresponding library and associated design kit is available for multi-project wafer (MPW) runs. Several applications of this platform technology in communications, biomedicine, sensing, as well as a few special fields of photonics are treated in more detail.

CMOS-compatible photonic devices for single-photon generation

“…2 illustrates the flow of fabricating silicon photonic crystal (PhC) slow-light waveguides using silicon-on-insulator (SOI) wafers [6]. With the above definition, devices based on materials beyond silicon, such as silicon nitride and Hydex also fall into the category of CMOS-compatible platforms [7,8]. In this paper, we focus on silicon-based devices.…”

Photonic Integrated Circuits for Communication Systems

“…The transparency window of both materials allows for the realization of low-loss waveguides over a wide wavelength range (400 nm-2.35 μm). Propagation losses as low as 5 × 10 -4 dB/cm are achieved [8].…”

Photonics Packaging Made Visible

“…The following examples all use the low-loss silicon-nitride based TriPleX [2,3,6] waveguide platform, which is based on several layers of Si 3 N 4 and SiO 2 . TriPleX has the advantage over the other dielectrics technologies that the properties of the waveguide, such as, e.g., the effective index contrast, can be tuned depending on geometrical design, well beyond the variations in waveguide height and width possible in the other technologies.…”

“…The presented devices are based on the TriPleX platform, a low-loss on-chip waveguide technology, which allows for control of wavelength, intensity, phase, mode size, polarization and input-output geometries. The technology is optimized for wavelengths from 400 up to 2000 nm [6].…”