Microphotonics devices based on silicon microfabrication technology

Ge-on-Si photonic devices for photonic-electronic integration on a Si platform

“…The light can be strongly confined in the submicron Si core, reflecting the large contrast of refractive index with SiO 2 /air cladding. Such Si WGs have been fabricated, patterning a top Si layer of Si-oninsulator (SOI) wafer with a CMOS process [13,14,15]. Low-loss propagation has been realized even at a bending with the radius as small as a few microns.…”

“…Low-loss propagation has been realized even at a bending with the radius as small as a few microns. Small sizes of ring resonators [15] and arrayed waveguide gratings (AWGs) [16] have been also realized for wavelength filters applicable to the wavelength division multiplexing (WDM) communications. These waveguide-based passive devices can be monolithically integrated on a Si platform, although there remain issues such as propagation losses due to the sidewall roughness (typically 1 dB/cm for channel WGs at present [17]) and the nanometer-scale error in WG size preventing the precise control of operation wavelengths in WDM filters.…”

Proposal of multiple-slot silica high-mesa waveguide for infrared absorption

“…Infrared absorption [1] based breath-content analysis using an optical integrated circuit has been studied widely for health monitoring [2,3,4] given the presence of various diseasemarkers [1,5,6] in breath-contents and the ppm-order sensing ability of infrared absorption. Additionally, the use of optical integrated circuits [7] is a promising solution for realizing the meter-long optical path length of regular gas cell [1,6,8,9] within a compact area considering the capability of realizing small radius of curvature. One of the critical issues with infrared sensing is the portion of light profiles outside of the waveguide (Γ air ), which can be used for sensing.…”

Wideband polarization splitter and rotator with large fabrication tolerance and simple fabrication process

“…Silicon-on-insulator (SOI) microphotonic devices are very attractive thanks to their complementary metal oxide semiconductor (CMOS)-compatible fabrication technology, their high refractive index contrast, and compact size [1]. Those advantages make SOI microphotonic devices promising candidates for all-optical signal processing subsystems.…”