Silicon Periodic Structures and their Liquid Crystal Composites

2009 ◽  
Vol 156-158 ◽  
pp. 547-554 ◽  
Author(s):  
Ekaterina V. Astrova ◽  
V.A. Tolmachev ◽  
Yulia A. Zharova ◽  
Galya V. Fedulova ◽  
A.V. Baldycheva ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Periodic Structures ◽  
Electrochemical Etching ◽  
Photonic Band Gap ◽  
Side Wall ◽  
Reflection And Transmission ◽  
One Dimensional ◽  
Advantages And Disadvantages ◽  
Infra Red ◽  
Photonic Band

This paper summarises results on the design, fabrication and characterisation of one-dimensional (1D) Photonic Crystals (PCs) for silicon micro-photonics. Anisotropic and photo-electrochemical etching were used to obtain silicon wall arrays with a high aspect ratio. The characteristics of these wet etching techniques, including their advantages and disadvantages are considered. Optical reflection and transmission spectra of the photonic structures fabricated were characterised by Fourier Transform Infra-Red (FTIR) micro-spectroscopy over a wide spectral range of =1.5-14.5m. These measurements reveal that side-wall roughness impacts the optical properties of 1D PCs. Problems associated with Photonic Band-Gap (PBG) tuning in periodic structures infiltrated with nematic liquid crystals are discussed. A design of a composite 1D PC on an SOI platform for electro-tuning is proposed. The structure was fabricated and tuning due to an electro-optical effect with E7 liquid crystal filler was demonstrated.

scholarly journals Theoretical Study of Tunable Optical Resonators in Periodic and Quasiperiodic One-Dimensional Photonic Structures Incorporating a Nematic Liquid Crystal

Photonics ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 150
Author(s):  
Youssef. Trabelsi ◽  
Walid. Belhadj ◽  
Naim. Ben Ali ◽  
Arafa H. Aly
Keyword(s):  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Photonic Band Gap ◽  
Defect Mode ◽  
Periodic Lattice ◽  
Local Defect ◽  
Strong Light ◽  
One Dimensional ◽  
Resonant Modes ◽  
Photonic Band

In this work, the transfer matrix method (TMM) is employed to investigate the optical properties of one-dimensional periodic and quasiperiodic photonic crystals containing nematic liquid crystal (NLC) layers. This structure is expressed as (ABC)J(CBA)J and made of alternated layers of isotropic dielectrics SiO2 (A), BGO (B) and nematic liquid crystal (C). The simulation study shows that the proposed ternary configuration exhibits tunable defect mode within the photonic band gap (PBG) that can be manipulated by adjusting the thicknesses of NLC layers in order of the periodic lattice. In addition, the optimized structure permits for strong confinement light giving rise to an optical microcavity. The application of an applied voltage into NLC layers enables improving the sensitivity by guiding the local defect mode. It has been also shown that by applying quasiperiodic inflation according to Rudin Shapiro Sequence (RSS) scheme to main periodic structure, several tunable resonant modes appear within the PBG. The presence of such sharp resonant peaks reflects that the quasiperiodic NLC-based structure behaves like multiple microcavites with strong light-matter coupling.

scholarly journals Electrically color-tunable defect mode lasing in one-dimensional photonic-band-gap system containing liquid crystal

2003 ◽  
Vol 82 (21) ◽  
pp. 3593-3595 ◽  
Author(s):  
Ryotaro Ozaki ◽  
Tatsunosuke Matsui ◽  
Masanori Ozaki ◽  
Katsumi Yoshino
Keyword(s):  
Liquid Crystal ◽  
Band Gap ◽  
Photonic Band Gap ◽  
Defect Mode ◽  
One Dimensional ◽  
Color Tunable ◽  
Photonic Band

TUNABLE 1D PHOTONIC CRYSTAL STRUCTURE BASED ON GROOVED Si INFILTRATED WITH LIQUID CRYSTAL E7

2007 ◽  
Vol 06 (05) ◽  
pp. 333-337
Author(s):  
V. A. TOLMACHEV ◽  
E. V. ASTROVA ◽  
J. A. PILYUGINA ◽  
T. S. PEROVA ◽  
R. A. MOORE
Keyword(s):  
Liquid Crystal ◽  
Photonic Crystal ◽  
Photonic Band Gap ◽  
Short Wave ◽  
Isotropic Phase ◽  
Initial Alignment ◽  
One Dimensional ◽  
Homeotropic Alignment ◽  
Photonic Band ◽  
Wave Edge

Tuning of a photonic band gap (PBG) in a composite one-dimensional photonic crystal infiltrated with nematic liquid crystal (LC) E7 has been evaluated by simulations. It has been found that a sufficient shift of the short wave edge can be obtained only in structures with a pronounced initial alignment of a LC director in the grooves of a single crystalline Si matrix. The largest effect Δλedge = 0.52 μm is predicted for the reorientation of LC molecules from planar homogeneous alignment along the grooves to homeotropic alignment with respect to the Si walls due to an electro-optical effect. The shift in PBG due to thermal tuning resulting from the transition of LC from mesophase to the isotropic phase (Δλedge = 0.4 μm) is less than that due to electric tuning. Thermo-tuning has been demonstrated experimentally, and PBG shift as high as Δλedge = 0.25 μm has been achieved.

Observation of Enhanced Faraday Effect in Garnet-Based Magnetophotonic Crystals

2004 ◽  
Vol 834 ◽  
Author(s):  
A. A. Fedyanin ◽  
D. Kobayashi ◽  
K. Nishimura ◽  
H. Uchida ◽  
M. Inoue ◽  
...  
Keyword(s):  
Faraday Rotation ◽  
Faraday Effect ◽  
Silicon Oxide ◽  
Photonic Band Gap ◽  
One Dimensional ◽  
Garnet Films ◽  
Faraday Rotation Angle ◽  
Magnetophotonic Crystals ◽  
Iron Garnet ◽  
Photonic Band

ABSTRACTThe fabrication of one-dimensional magnetophotonic crystals (MPC) composed from Bi-substituted yttrium-iron-garnet films separated by the silicon oxide layers is presented. The enhancement of the Faraday rotation angle is observed at the spectral regions of the photonic band gap edges. The effective Faraday rotation achieves the values up to 1.5 degrees per micron at 1100-nm-wavelength.

Sign in / Sign up

Export Citation Format

Share Document