scholarly journals Subwavelength-Diameter Silica Wire and Photonic Crystal Waveguide Slow Light Coupling

2007 ◽  
Vol 2007 ◽  
pp. 1-5 ◽  
Author(s):  
Ziyang Zhang ◽  
Ulf Andersson ◽  
Min Qiu
Keyword(s):  
Photonic Crystal ◽  
Slow Light ◽  
Power Transmission ◽  
Coupling Efficiency ◽  
Three Dimensional ◽  
Slab Waveguide ◽  
Photonic Crystal Waveguide ◽  
Central Wavelength ◽  
Lattice Constants ◽  
Light Region

Counter-directional coupling between subwavelength-diameter silica wire and single-line-defect two-dimensional photonic crystal slab waveguide is studied numerically using parallel three-dimensional finite-different time-domain method. By modifying silica wire properties or engineering photonic crystal waveguide dispersion band, the coupling central wavelength can be moved to the slow light region and the coupling efficiency improves simultaneously. One design gives 82% peak power transmission from silica wire to photonic crystal waveguide over an interacting distance of 50 lattice constants. The group velocity is estimated as 1/35 of light speed in vacuum.

On the role of evanescent modes and group index tapering in slow light photonic crystal waveguide coupling efficiency

2011 ◽  
Vol 98 (3) ◽  
pp. 031107 ◽  
Author(s):  
Amir Hosseini ◽  
Xiaochuan Xu ◽  
David N. Kwong ◽  
Harish Subbaraman ◽  
Wei Jiang ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Slow Light ◽  
Coupling Efficiency ◽  
Group Index ◽  
Photonic Crystal Waveguide ◽  
Waveguide Coupling

Modification of optical response in quantum dots embedded in a photonic crystal waveguide via photonic band engineering

2012 ◽  
Vol 1438 ◽  
Author(s):  
Nobuhiko Ozaki ◽  
Hayato Yoneda ◽  
Koichi Takeuchi ◽  
Hisaya Oda ◽  
Naoki Ikeda ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Photonic Crystal ◽  
Optical Switching ◽  
Slow Light ◽  
Photonic Crystal Waveguide ◽  
Purcell Effect ◽  
Carrier Relaxation ◽  
Lattice Constants ◽  
Band Engineering ◽  
Photonic Band

ABSTRACTWe propose to use Purcell effect emerged at slow light regions in photonic crystal waveguide (PC-WG) modes for controlling the relaxation time of excited carriers in QDs. Straight GaAs PC-WGs including InAs-QDs with various lattice constants of PC were prepared in order to control the wavelength of the slow light in the PC-WG modes. PL measurements of the PC-WGs indicated enhancements of emission from QDs at the localized wavelength of slow light regions due to the Purcell effect. The enhanced emission peak wavelength was continuously shifted with the PC lattice constant. These results suggest that the PC-WG can be utilized to modify the spontaneous emission rate and carrier relaxation time of the embedded QD. This modification can be applied and useful for various QD-based optical devices as well as our proposed all-optical switching device based on PC-WG/QD.

scholarly journals Double-layer graphene on photonic crystal waveguide electro-absorption modulator with 12 GHz bandwidth

Nanophotonics ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 2377-2385 ◽  
Author(s):  
Zhao Cheng ◽  
Xiaolong Zhu ◽  
Michael Galili ◽  
Lars Hagedorn Frandsen ◽  
Hao Hu ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Double Layer ◽  
Slow Light ◽  
Modulation Depth ◽  
Photonic Crystal Waveguide ◽  
Optical Modulators ◽  
Layer Graphene ◽  
Silicon Photonic ◽  
On Chip ◽  
Silicon Based

AbstractGraphene has been widely used in silicon-based optical modulators for its ultra-broadband light absorption and ultrafast optoelectronic response. By incorporating graphene and slow-light silicon photonic crystal waveguide (PhCW), here we propose and experimentally demonstrate a unique double-layer graphene electro-absorption modulator in telecommunication applications. The modulator exhibits a modulation depth of 0.5 dB/μm with a bandwidth of 13.6 GHz, while graphene coverage length is only 1.2 μm in simulations. We also fabricated the graphene modulator on silicon platform, and the device achieved a modulation bandwidth at 12 GHz. The proposed graphene-PhCW modulator may have potentials in the applications of on-chip interconnections.

scholarly journals Towards lab-on-chip ultrasensitive ethanol detection using photonic crystal waveguide operating in the mid infrared

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali Rostamian ◽  
Ehsan Madadi-Kandjani ◽  
Hamed Dalir ◽  
Volker J. Sorger ◽  
Ray T. Chen
Keyword(s):  
Photonic Crystal ◽  
Slow Light ◽  
High Sensitivity ◽  
Guided Wave ◽  
Silicon On Insulator ◽  
Group Index ◽  
Photonic Crystal Waveguide ◽  
Mid Infrared ◽  
Lab On Chip ◽  
On Chip

Abstract Thanks to the unique molecular fingerprints in the mid-infrared spectral region, absorption spectroscopy in this regime has attracted widespread attention in recent years. Contrary to commercially available infrared spectrometers, which are limited by being bulky and cost-intensive, laboratory-on-chip infrared spectrometers can offer sensor advancements including raw sensing performance in addition to use such as enhanced portability. Several platforms have been proposed in the past for on-chip ethanol detection. However, selective sensing with high sensitivity at room temperature has remained a challenge. Here, we experimentally demonstrate an on-chip ethyl alcohol sensor based on a holey photonic crystal waveguide on silicon on insulator-based photonics sensing platform offering an enhanced photoabsorption thus improving sensitivity. This is achieved by designing and engineering an optical slow-light mode with a high group-index of n g  = 73 and a strong localization of modal power in analyte, enabled by the photonic crystal waveguide structure. This approach includes a codesign paradigm that uniquely features an increased effective path length traversed by the guided wave through the to-be-sensed gas analyte. This PIC-based lab-on-chip sensor is exemplary, spectrally designed to operate at the center wavelength of 3.4 μm to match the peak absorbance for ethanol. However, the slow-light enhancement concept is universal offering to cover a wide design-window and spectral ranges towards sensing a plurality of gas species. Using the holey photonic crystal waveguide, we demonstrate the capability of achieving parts per billion levels of gas detection precision. High sensitivity combined with tailorable spectral range along with a compact form-factor enables a new class of portable photonic sensor platforms when combined with integrated with quantum cascade laser and detectors.

scholarly journals Probing molecular absorption under slow-light propagation using a photonic crystal waveguide

2012 ◽  
Vol 37 (23) ◽  
pp. 4934 ◽  
Author(s):  
Isabelle Dicaire ◽  
Alfredo De Rossi ◽  
Sylvain Combrié ◽  
Luc Thévenaz
Keyword(s):  
Photonic Crystal ◽  
Light Propagation ◽  
Slow Light ◽  
Photonic Crystal Waveguide ◽  
Molecular Absorption
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