scholarly journals Design of a Curved Shape Photonic Crystal Taper for Highly Efficient Mode Coupling

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 585
Author(s):  
Reyhaneh Jannesari ◽  
Thomas Grille ◽  
Cristina Consani ◽  
Gerald Stocker ◽  
Andreas Tortschanoff ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Hexagonal Lattice ◽  
Coupling Efficiency ◽  
Smooth Transition ◽  
Square Lattice ◽  
Group Index ◽  
Photonic Crystal Waveguide ◽  
Silicon Rods

The design and modeling of a curved shape photonic crystal taper consisting of Si rods integrated with a photonic crystal waveguide are presented. The waveguide is composed of a hexagonal lattice of Si rods and optimized for CO2 sensing based on absorption spectroscopy. We investigated two different approaches to design a taper for a photonic crystal waveguide in a hexagonal lattice of silicon rods. For the first approach (type 1), the taper consists of a square lattice taper followed by a lattice composed of a smooth transition from a square to a hexagonal lattice. In the second approach (type 2), the taper consists of a distorted hexagonal lattice. Different shapes, such as convex, concave, and linear, for the curvature of the taper were considered and investigated. The structure of the taper was improved to enhance the coupling efficiency up to 96% at a short taper length of 25 lattice periods. The finite-difference time-domain (FDTD) technique was used to study the transmission spectrum and the group index. The study proves the improvement of coupling using a curved shape taper. Controlling the group index along the taper could be further improved to enhance the coupling efficiency in a wider spectral range.

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

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 Near-Unity Coupling Efficiency of a Quantum Emitter to a Photonic Crystal Waveguide

2014 ◽  
Vol 113 (9) ◽  
Author(s):  
M. Arcari ◽  
I. Söllner ◽  
A. Javadi ◽  
S. Lindskov Hansen ◽  
S. Mahmoodian ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Coupling Efficiency ◽  
Photonic Crystal Waveguide ◽  
Quantum Emitter

Active Photonic Crystals Based multiplexer

2006 ◽  
Vol 934 ◽  
Author(s):  
Principia Dardano ◽  
Vito Mocella ◽  
Luigi Sirleto ◽  
Luigi Moretti ◽  
Ivo Rendina
Keyword(s):  
Refractive Index ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Photonic Crystal ◽  
Photonic Crystals ◽  
Square Lattice ◽  
Two Dimensional ◽  
Optical Effect ◽  
Electro Optical Effect ◽  
Silicon Rods

ABSTRACTIn the last years, in order to achieve active tuning of photonic crystals devices, the possibility to use liquid crystal inside photonic crystals has been explored.On this line of argument, in this paper, we numerically investigate a tunable T-shaped waveguide diplexer, based on a two-dimensional square lattice photonic crystal composed of silicon rods in a liquid crystals. We prove that complete splitting of the entire input wavelengths range in two sub-ranges symmetrical with respect to the middle (switching) wavelength, and propagating in right and left arms respectively, can be achieved. Moreover, changing the refractive index of liquid crystals by electro-optical effect, a tuning of switching wavelength of about 60 nm can be obtained.

Characteristics of 45° photonic crystal ring resonators based on square-lattice silicon rods

2010 ◽  
Vol 6 (3) ◽  
pp. 203-206 ◽  
Author(s):  
Ji-bo Bai ◽  
Jun-qin Wang ◽  
Xi-yao Chen ◽  
Jun-zhen Jiang ◽  
Hui Li ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Ring Resonators ◽  
Square Lattice ◽  
Silicon Rods

Experiments with Phase-Delay and Time-Delay Methods for Slow Light in Photonic Crystal Waveguide

2013 ◽  
Vol 684 ◽  
pp. 290-294
Author(s):  
Hui Lu ◽  
Li Jun Zhang ◽  
Zhan Qi Zheng ◽  
Yi Heng Zhang ◽  
Yong Qing Leng
Keyword(s):  
Photonic Crystal ◽  
Time Delay ◽  
Theoretical Result ◽  
Slow Light ◽  
Phase Delay ◽  
Silicon On Insulator ◽  
Group Index ◽  
Experimental Measurements ◽  
Photonic Crystal Waveguide ◽  
Good Agreement

In this paper, we report the experimental measurements of the group index of a photonic crystal waveguide based on silicon-on-insulator slab. The time-delay of the pulse is also measured, and it is in good agreement with the theoretical result calculated according to the group index with the phase-delay method, which is about 4.7ps.

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