Electric field sensor based on electro-optic polymer refilled silicon slot photonic crystal waveguide coupled with bowtie antenna

We present the design of a compact and highly sensitive electric field sensor based on a bowtie antenna-coupled slot photonic crystal waveguide (PCW). An electro-optic (EO) polymer with a large EO coefficient, r33=100pm/V, is used to refill the PCW slot and air holes. Bowtie-shaped electrodes are used as both poling electrodes and as receiving antenna. The slow-light effect in the PCW is used to increase the effective in-device r33>1000pm/V. The slot PCW is designed for low-dispersion slow light propagation, maximum poling efficiency as well as optical mode confinement inside the EO polymer. The antenna is designed for operation at 10GHz.Comment: 7 pages, 5 figures, conference. "Electric field sensor based on electro-optic polymer refilled silicon slot photonic crystal waveguide coupled with bowtie antenna," Proc. SPIE 8624, 862418 (2013

On-chip methane sensing by near-IR absorption signatures in a photonic crystal slot waveguide,”

We demonstrate a 300 μm long silicon photonic crystal (PC) slot waveguide device for on-chip near-infrared absorption spectroscopy, based on the Beer-Lambert law for the detection of methane gas. The device combines slow light in a PC waveguide with high electric field intensity in a low-index 90 nm wide slot, which effectively increases the optical absorption path length. A methane concentration of 100 ppm (parts per million) in nitrogen was measured

Wide Dynamic Range Specific Detection of Therapeutic Drugs by Photonic Crystal Microcavity Arrays

Abstract: Six orders of magnitude wide dynamic range (0.1ng/ml to over 100g/ml), label-free detection of gentamicin small molecules with silicon photonic crystal microcavity biosensors multiplexed by multimode interference power splitters was experimentally demonstrated. Detection specificity was confirmed. The devices were fabricated with CMOS compatible 193nm UV lithography process on a silicon-on-insulator (SOI) wafer. The device comprises a 1×4 MMI (multimode interference) power splitter that splits the input light into four optical paths. On each path, an L-type PC microcavity sensor with different sensitivity is located, namely L3, L13, L55 and L13 with defect holes. Before applying any target solution, resonance spectrum for each device was recorded and the resonance position was used as baseline. The chip is then incubated in target solution for 40 min. Several concentrations of the target were measured. After each incubation, the chip was washed with PBS and new spectra were tested and resonance positions were recorded. From the data points i

Wide Dynamic Range Sensing in Photonic Crystal Microcavity Biosensors

Abstract: Typical L-type photonic crystal (PC) microcavities have a dynamic range of approximately 3-4 orders of magnitude in biosensing. We experimentally demonstrated that multiplexing of PC sensors with different geometry can achieve a wide dynamic range covering 6 orders of magnitude with potential for 8 or more orders with suitable optimization. We fabricated PCWs on silicon-on-insulator (SOI) devices with a 250nm top silicon layer, a 3µm buried oxide layer

Photonic crystal Microarray Nanoplatform for High Throughput Detection of Biomolecules

ABSTRACT We present preliminary designs and experimental results for creating a microarray nanoplatform based on twodimensional photonic crystal devices in silicon. Multiple photonic crystal microcavities are coupled along the length of a single photonic crystal waveguide that undergo resonance wavelength shifts when an antibody-antibody binding event occurs in the immediate vicinity of the corresponding photonic crystal microcavity. The microarray nanoplatform enables high throughput measurements of multiple antibody-antibody interactions via a single optical waveguide transmission measurement

Coupling loss minimization of slow light slotted photonic crystal waveguides using mode matching with continuous group index perturbation

We experimentally demonstrate highly efficient coupling into a slow light slotted photonic crystal waveguide. With optical mode converters and group index tapers that provide good optical mode matching and impedance matching, a nearly flat transmission over the entire guided mode spectrum of 68.8 nm range with 2.4 dB minimum insertion loss is demonstrated. Measurements also show up to 20 dB baseline enhancement and 30 dB enhancement in the slow light region, indicating that it is possible to design highly efficient and compact devices that benefit from the slow light enhancement without increasing the coupling loss.This paper was published in Optics Letters and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/ol/home.cfm. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law

Guided-mode-resonance-coupled plasmonic-active SiO₂ nanotubes for surface enhanced Raman spectroscopy

We demonstrate a surface enhanced Raman scattering (SERS) substrate by integrating plasmonic-active SiO₂ nanotubes into Si₃N₄ gratings. First, the dielectric grating that is working under guided mode resonance (GMR) provides enhanced electric field for localized surface plasmon polaritons on the surface of metallic nanoparticles. Second, we use SiO₂ nanotubes with densely assembled silver nanoparticles to provide a large amount of "hot spots" without significantly damping the GMR mode of the grating. Experimental measurement on Rhodamine-6G shows a constant enhancement factor of 8 ~ 10 in addition to the existing SERS effect across the entire surface of the SiO₂ nanotubes. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4714710]Keywords: Silver Electrode, Single Molecule, Scattering, SER