Low-loss rib waveguides containing Si nanocrystals embedded in SiO2

Abstract

We report on the study and modeling of the structural and optical properties of rib-loaded waveguides working in the 600-900-nm spectral range. A Si nanocrystal ͑Si-nc͒ rich SiO 2 layer with nominal Si excess ranging from 10% to 20% was produced by quadrupole ion implantation of Si into thermal SiO 2 formed on a silicon substrate. Si-ncs were precipitated by annealing at 1100°C, forming a 0.4-m-thick core layer in the waveguide. The Si content, the Si-nc density and size, the Si-nc emission, and the active layer effective refractive index were determined by dedicated experiments using x-ray photoelectron spectroscopy, Raman spectroscopy, energy-filtered transmission electron microscopy, photoluminescence and m-lines spectroscopy. Rib-loaded waveguides were fabricated by photolithographic and reactive ion etching processes, with patterned rib widths ranging from 1 to 8 m. Light propagation in the waveguide was observed and losses of 11 dB/ cm at 633 and 780 nm were measured, modeled and interpreted.

Linear and nonlinear optical properties of Si nanocrystals in SiO2 deposited by plasma-enhanced chemical-vapor deposition

“…By controlling the size of the particles, the confinement potential can be modified and, consequently, their emission can be tuned from 1.2 to 1.75 eV. [1][2][3][4][5] On the other hand, the low absorption coefficient makes Si-nc attractive as active medium in waveguide structures. Recently, their nonlinear optical properties have been also investigated, for promising applications such as all-optical switching.…”

Metal island film-based structures for sensing using spectrophotometry and ellipsometry

“…In order to obtain the average grain size and nanoparticle morphology Bright field (BF) transmission electron microscopy (TEM) images are done in a Jeol 2010F field emission gun microscope operated at 200 KV. In order to differentiate between Si and SiO2 and achieve clear composition images, energy filtered TEM (EFTEM) is made [16,17].…”

Evaluation of losses and group effective refractive index of Er3+:Ti:LiNbO3 optical waveguides

“…In the last few years, passive and active optical waveguides based on LiNbO 3 substrates have attracted great interest in the field of integrated optics for devices such as optical modulators, switches, filters, lasers, amplifiers, and nonlinear optical converters, to be used in high-speed optical communications and sensors. Knowledge of the behavior of optical waveguides is essential for the fabrication of more complex integrated circuits.…”

“…For the measurement of optical losses, destructive and non-destructive methods are the techniques most commonly used. Over the past few years, several papers have addressed the measurement and evaluation of losses in the above mentioned optical waveguides [1][2][3][4][5]. Among the non-destructive techniques, some of the most commonly used are the interferometry methods [5][6][7].…”