Session Overview |
Photonics materials - Bloc 3Room: International 2 |
Date: Thursday, June 07 |
15:30 |
Terahertz photoconductivity of germanium inverse opal structures
Main Author: Mary Alvean Narreto Organization: University of Alberta, Canada We investigate the ultrafast photoconductivity of amorphous germanium and its macroporous inverse opal structure counterparts using time-resolved terahertz spectroscopy. |
15:45 |
Photoluminescence dynamics of functionalized two-dimensional silicon nanosheets
Main Author: Mary Alvean Narreto Organization: University of Alberta, Canada We investigate the photoluminescence (PL) dynamics of functionalized two-dimensional freestanding silicon nanosheets (SiNSs). The PL is shown to be an intrinsic property and the carrier dynamics is characterized as a band-to-band recombination process with diffusion-limited charge transport. |
16:00 |
Optochemical waves: from bio-inspired optics, 3-D printing to materials for all-optical encoding
Main Author: Kalaichelvi Saravanamuttu Organization: McMaster University, Canada Optochemical waves are nonlinear waves of light, which are characterized by their ability to travel without diverging through a medium. When elicited with laser or weak, incoherent (incandescent, LED) light in photoresponsive systems that undergo permanent chemical changes, they inscribe cylindrical channels, populate these waveguides as optical modes and exhibit several properties reminiscent of spatial solitons. This seminar highlights how optochemical waves have opened unconventional routes to three different applications. The first are Waveguide Encoded Lattices (WELs) - which like an insect’s compound eye - possess a significantly enhanced field of view. Fabricated by launching thousands of optochemical waves in a flexible, robust photopolymer medium, WEL lattices can serve as encapsulants of light-harvesting devices or light-shaping conformal coatings on LEDs. The second application exploits the non-divergent nature of optochemical waves and shows that by embedding patterns within these waves, it is possible to print seamless 3-D objects both in dielectric and metallodielectric materials. This is challenging to achieve with current 3-D printers. Finally, we show how the soliton-like interactions of optochemical waves within a photopolymer cube enable spontaneous transfer of binary information between light beams and create strategies for all-optical encoding. |
16:25 |
Dynamic light shaping for LED sources using liquid crystals; The last mile in smart lighting
Main Author: Tigran Galstian Organization: Université Laval, Canada This presentation will focus on the recently developed technology of dynamic control of light’s spatial distribution. It is based on the same mechanism as the one used in flat panel liquid crystal displays (LCDs). However, many of traditional components of LCDs (such as polarizers, thin film transistors and color filters) are eliminated to obtain very efficient (high transmittance) and low cost devices that are capable of symmetric broadening of light (by a factor of up to 25 times) or “angularly stretching” it in various planes allowing the transformation of light from a circular into rectangular shaped beams. |
16:40 |
New insights into solid state laser cooling using oxyfluoride glass-ceramics
Main Author: Jyothis Thomas Organization: École Polytechnique de Montréal, Canada We report a study on the optical properties of purified ytterbium doped oxyfluoride glass-ceramics for laser cooling applications as a function of the crystallization temperature. The absorption and photoluminescence spectra, as well as the lifetime and the internal quantum yield are characterized. Pump wavelength dependent temperature change of the samples are measured using a fiber Bragg grating sensor |
16:55 |
Enhanced THz Absorption of a One-dimensional Photonic Crystal Incorporating a Gated Monolayer Graphene in External Magnetic Field
Main Author: Arezou Rashidi Organization: University of Tabriz, Iran (Islamic Republic of Using 4×4 transfer matrix method, the terahertz (THz) absorption properties of a monolayer graphene placed on top of a one-dimensional photonic crystal is investigated under perpendicular magnetic bias (Faraday Geometry). Since graphene is grown on C-terminated surface of silicon carbide, because of the low doping level in graphene, the response of electrons to the magnetic field is inspected at the quantum regime. Based on different optical response of graphene for right- and left-handed circularly polarized light and, magnetic circular dichroism, the enhanced absorption in the proposed structure is achieved at certain polarization state. The advantage of this work is the possibility of achieving enhanced absorption at low magnetic fields. Moreover, application of gate voltage provides another tunability of absorption. Therefore, appropriate choice of magnetic and electric biases can lead to the enhanced absorption in our proposed structure which may be beneficial for designing tunable graphene-based THz absorbers. |
17:10 |
Half Hetch Slot waveguides for Low-Cost Integration of CMOS compatible low refractive index active materials in Silicon Photonics
Main Author: Régis Orobtchouk Organization: Institut of Nanotechnologies of Lyon (INL), France Passive basic Building blocks used for an optical routing of information on half etch slot based waveguide configuration have been designed, fabricated and characterized on a CMOS compatible silicon plateform. Such waveguide configuration allows hybridization of low refractive index materials as HFO2 and AlN potentially interesting for boosting optical functionalities of integrated circuits. |
17:25 |
Signal Enhancement from Silicon Slot Waveguide with ECR-PEVCD Erbium-Doped Silica Cladding
Main Author: Jeremy Miller Organization: McMaster University, Canada We report on erbium-doped silica films that have been synthesized using ECR-PECVD and doped in-situ through a magnetron sputtering tool. These films are deposited onto silicon slot waveguides structures. Film and waveguide properties and gain measurements are presented. |
17:40 |
Development of modified photonic surfaces for application in sensing
Main Author: Sabad-e- Gul Organization: Dublin Institute of Technology, Ireland The aim of the presented research is to fabricate and test portable holographic sensors for analytes in liquids. The characteristics that are targeted are the simplicity of operation, selectivity, sensitivity and relatively low cost. In order to achieve this aim, photonic devices are fabricated by holographic patterning, with a view to their application in environmental and biomedical sensing. Different types of analyte sensitive materials are used to functionalise the surfaces of these photonic devices. |