An analysis of the dispersion relation of <i>SiO</i><sub>x</sub> submicron optical waveguides in the visible and IR spectral range is
presented. Here is considered that the refractive index <i>(n)</i> of <i>SiO</i><sub>x</sub> can be tuned in the range from n=<i>1.457-2 for 2>x>1,</i>
and a film thickness from 50<i>nm</i> to 1000<i>nm</i>. Starting from the dispersion relation and the distribution of the electric field
in the waveguide; cutoff wavelength, cutoff thickness, effective refractive index, effective guide thickness and
confinement factor of a selected mode are calculated.
Design of straight and S-bend optical channel waveguides based on silver ion implantation in SiO<sub>2</sub> substrates is
presented. 3D Beam Propagation Method (BPM) calculations are used for the design of the waveguides based on step
index profiles produced from a sequential multiple ion implantation process. An analysis of modal optical confinement
was done by means of the Effective Index Method (EIM) for selecting the right dimensions of the channel waveguides.
Core index values between 1.4623-1.4662 are obtained, depending on the fluence, are considered. Depth and width for
the waveguides were chosen to provide single mode operation. Bending losses are determined as function of bending
radius, refractive index change (Δn), and wavelength.
The study of surface plasmon-polaritons interactions in metallic nanostructures has been a topic of interest during last years due to their use in various areas such as the photonics, chemistry and biology. Example of use is found in biosensors for the efficient detection of biological analyte and in nanophotonic elements for on-chip photonics.
Here, we study the interactions properties of localized surface plasmons in a hybrid waveguiding structure made of bi-dimensional array of gold nanowires vertically integrated on silicon-on-insulator waveguides across the near infrared spectrum. With the use of near-field scanning optical microscopy (NSOM) in perturbation mode, we qualitatively obtained the spectral response of such hybrid structure through intensity near field maps of the light propagation. These experimental results demonstrate that metallic nanostructures integrated on silicon are suitable for the development of localized surface plasmon integrated devices or metallic metamaterials.
In this work a study of the effects on the optical properties of channel waveguides in Nd:YAG crystals fabricated with
different proton implantations doses is presented. The channel structure was achieved by using an electroformed mask
with openings through which the protons were implanted. The optical properties studied included microphotographs, the
transversal modal distribution at visible wavelengths, the photoluminescence spectra and the laser emission. The laser
performance of the waveguides was obtained in a resonant cavity configuration with mirrors held onto the polished end
faces of the waveguides.
Optical waveguides have been obtained by silver ion implantation on fused silica substrates. First results of a
methodology oriented to design optical waveguides with silver nanoparticles in a dielectric matrix are presented.
Simulation of ion implantation is based on SRIM code and is correlated with a refractive index increase Δ<i>n</i> calculated as
a function of the chemical composition. Effective refractive indices of the propagation modes are determined by prismcoupling
In this work we present the laser performance of channel waveguides which operate at 1064 nm at
room temperature. These channels were made on Nd: YAG crystal by proton implantation with different widths (10, 15
and 20 μm) forming sets of 10 waveguides which are separated by a distance of 215 μm. The results shown are
transversal mode distribution, propagation losses, absorption and luminescence spectra and laser emission characteristics
such as pump power threshold and slope efficiency. The spectroscopic characterization indicates that the optical
properties of the waveguide in comparison with the bulk material are preserved after the implantation process and that
this is a potential technique to develop compact and efficient lasers.
A typical rear projection screen is formed by two components: Fresnel lens and lenticular/diffuser plate. This work
provides a technique to determinate color uniformity across the screen. Initial results of color uniformity of Fresnel lens
and lenticular/diffuser plate indicates a very good uniformity.
Optical waveguides have been formed by proton implantation in Nd:YVO<sub>4</sub> crystals using energies from 0.4 to 1 MeV and doses of the order of 1×10<sup>16</sup> ions/cm<sup>2</sup>. Double implants were realized to generate wide optical barriers and a triple implant produced stacked waveguides. Waveguide characterization comprises propagation modes, refractive index profiles, near field imaging and spectroscopic properties. Differences between the waveguides were found in terms of mode confinement which is important for integrated devices.
Optical waveguides have been produced in Nd:YAG and Nd:YVO<sub>4</sub> crystals by either proton or carbon implantation. The analysis includes refractive index profiles, spectroscopic properties and particularly laser emission characteristics in the YAG guides. Typical optical barrier profiles were obtained when protons were used. In the case of YVO<sub>4</sub>, carbon implantation produced a considerable refractive index variation in the guiding region, increasing the ordinary index and reducing the extraordinary index. The spectroscopic studies show that emission bands coming from the <sup>4</sup>F<sub>3/2</sub> level are not significantly altered by the ion beam process, thus maintaining the crystal quality in the guiding region. The YAG waveguides exhibit good laser emission characteristics at 1 064 nm and high stability in the CW regime.
In this work we report the performance of CW Nd:YAG waveguide lasers operating at 1064 nm at room temperature. The waveguides were fabricated by proton implantation and the main differences in the process of fabrication were the angle of implantation and the total dose implanted. The characterization of the waveguide refractive index profile induced by proton implantation and the main laser characteristics i.e. slope efficiency and threshold are presented. The results indicate that the optical properties of the waveguide in comparison with the bulk material are preserved after the implantation process and that this is a potential technique to develop compact and efficient lasers.
In this work, we present results of a simple technique to fabricate single mode fused fiber couplers. Couplers are fabricated in small mobile ceramic oven heated by gas flame to obtain a temperature uniformity, and a constant tension is maintained during fusion process to elongate the optical fibers. The fibers are tapered in order to close the cores and propitiate the evanescent field coupling. Optical properties of the resulting couplers, with different output power ratio, are analyzed.