In this numerical study, we show that by exploiting the advantages of the horizontal silicon slot waveguide structure the nonlinear interaction can be significantly increased compared to vertical slot waveguides. The deposition of a 20 nm thin optically nonlinear layer with low refractive index sandwiched between two silicon wires of 220 nm width and 205 nm height could enable a nonlinearity coefficient γ of more than 2 × 10⁷ W^-1km^-1.

We present a CMOS-compatible silicon nitride (Si3N4) waveguide technology platform suitable for monolithic co-integration with optoelectronics in the visible and <1.1μm near infrared wavelength region. With an optimized fabrication process employing low-temperature plasma enhanced chemical vapour deposition (PECVD) and reactive ion etching (RIE), propagation losses of 0.86dB/cm were achieved at λ=850nm for wire waveguides with a cross section of 600x250 nm2. As an example of application we show Mach-Zehnder interferometer based label-free optical detection of the S-protein/S-peptide interaction. Moreover, we present experimental steps towards the realisation of multi-channel biosensors using spiral shaped waveguide structures ensuring a small form factor

The fabrication of flexible low-loss, thin-film, foil-based polymer waveguides with grating couplers employing a high-volume industrial roll-to-roll process is demonstrated. The embossed waveguides feature propagation losses of less than $1\mathrm{dB}/\mathrm{cm}$ (633 nm, TE polarization), bending losses of $0.4–0.8\mathrm{dB}/360°$ for bending radii as small as 2 mm, and grating coupling efficiencies of up to 25%. In addition, the waveguides possess a thermo-optic coefficient of $-1.58\times {10}^{-4}1/°\mathrm{C}$. The fabricated waveguides are promising candidates for short-distance data communication as well as for sensing applications.

In this letter, we theoretically investigate the potential for further improvement of the slot waveguide structure in silicon-on-insulator at a wavelength of 1550 nm. Waveguide thickness and width, as well as slot thickness are optimized with respect to the optical power confined in the slot region by taking into account the modal behavior of the structure. A single-mode criterion is defined as a function of the geometry parameters