Investigation on optical integration between LED Mid-IR light sources and Si-based waveguides for sensing applications

Research on mid-IR silicon-based waveguides has recently received strong interest. Particularly, this paper focuses on one of the critical issues in micron-scale photonic integrated circuits, which is to efficiently couple a mid-IR LED (light emitting diode) light source to an external micron-scale waveguide. The optical coupling scheme is crucial for the exploitation of LED light sources in waveguide-based spectroscopic sensing applications. This paper reports optical coupling scheme between an LED mid-IR light source and a silicon rich silicon nitride (SiN) waveguide that could enable the use of LED-based light sources. Finally, the detection limit of the investigated device for carbon dioxide gas detection is calculated.

Numerical simulation of optical coupling between a microring resonator and a directly connected straight waveguide

We studied numerically optical coupling of whispering gallery modes of a microring resonator with modes of a radially directed straight waveguide connected to the microring. Optical outcoupling from the resonator through the waveguide was calculated for different widths of the latter. The output was maximized under conditions when the width fits an odd integer number of half-wavelengths of light inside the microring.

Optomechanical interaction between single-walled carbon nanotubes of various structures

We consider optomechanical interaction in an asymmetric structure of a carbon nanotubes dimer of different orientations and/or different atomic structures in the field of a plane wave or a focused Gaussian beam. Here we show that optical coupling in such the system can lead to nonreciprocal interactions between the constituents. We demonstrate that a non-conservative force is applied to the center of mass of an optically coupled nanotube dimer, resulting in an unexpected lateral action. The sign and magnitude of this force depend on abrupt phase transitions in the properties of the asymmetric dimer.