What is Photonic crystal: Definition and 15 Discussions
A photonic crystal is a periodic optical nanostructure that affects the motion of photons in much the same way that ionic lattices affect electrons in solids. Photonic crystals occur in nature in the form of structural coloration and animal reflectors, and, in different forms, promise to be useful in a range of applications.
In 1887 the English physicist Lord Rayleigh experimented with periodic multi-layer dielectric stacks, showing they had a photonic band-gap in one dimension. Research interest grew with work in 1987 by Eli Yablonovitch and Sajeev John on periodic optical structures with more than one dimension—now called photonic crystals.
Photonic crystals can be fabricated for one, two, or three dimensions. One-dimensional photonic crystals can be made of layers deposited or stuck together. Two-dimensional ones can be made by photolithography, or by drilling holes in a suitable substrate. Fabrication methods for three-dimensional ones include drilling under different angles, stacking multiple 2-D layers on top of each other, direct laser writing, or, for example, instigating self-assembly of spheres in a matrix and dissolving the spheres.
Photonic crystals can, in principle, find uses wherever light must be manipulated. Existing applications include thin-film optics with coatings for lenses. Two-dimensional photonic-crystal fibers are used in nonlinear devices and to guide exotic wavelengths. Three-dimensional crystals may one day be used in optical computers. Three-dimensional photonic crystals could lead to more efficient photovoltaic cells as a source of power for electronics, thus cutting down the need for an electrical input for power.
In 1D Photonic crystals, a defect can be introduced to create a defect/resonance mode and enable transmission. At first considerations, the thickness of the single defect layer determines the transmission frequency. Moreover, if it is a half-wavelength layer it will enable a resonance condition...
Im supposed to make model to demonstrate all-optical switching using a nonlinear effects of photonic crystals. And I will be using a directional coupler for this purpose. However I am having trouble in understanding the theory and concepts related to coupling / coupling length / use of...
hi, I'm currently talking about light, and I'm trying to find out if there is a material or a method that can flip a polariser's polarisation...
ie, if i apply a current, then this crystal changed from a clockwize polariser to an anti-clockwize polariser, and it is either a plastic or elastic...
Hi, I'm Sungdae studying in Korea.
In common, making a energy state in the photonic energy gap.
but i don't know exactly what a different single-mode-cavity and 'single'-mode-cavity?
Thanks
Hello!
I know how to calculate band structure and density of states of photonic crystal (example is pic.1)
Does anybody know how to plot such DOS maps?
The second picture is from the article about photonic crystal fibers by Rodrigo Amezcua.
I have calculated the band structure of an infinite photonic crystal structure by COMSOL.
So, I have an array of meanings of K-vector and different values of frequency V.
I need to calculate density of states (DOS). How can I calculate it?
Thanks.
I use transfer matrix method. I try to plot the phase Φ(ω) versus frequency ω graph in the vicinity of a band gap. The transmission coefficient t(ω) is
t(ω) = |t(ω)|*exp(i*Φ(ω))
from which I get the transmission phase
Φ(ω) = atan(t_imaginary(ω)/t_real(ω)).
Since I assume that -pi/2 ≦ Φ ≦...
I have one hollow core fiber, the core is around 20um, Numerical Aperture is
0.03. The spot size of Ti:Sapphire laser is around 2~2.5mm. So I used focal
length 50mm. But only very few power can be achieved (6uw). I wonder
the reason. Could someone please give me some suggestions?
Hello everyone, I am trying to understand COMSOL 3.5 and I am interested in Photonic crystal fibres and tapered optical fibres. First of all, could you please tell me what is the background of the layout? When you create a design/object, the rest area is air or I need to define another object as...
Hi,
I have this quite basic question regarding photonic crystals.
As I understand, a periodic dielectric structure (photonic crystal) has modes (spatial profiles) at discrete frequencies from:
\nabla \times \Big( \frac{1}{\epsilon(r)}\nabla \times H(r) \Big) = \frac{\omega^2}{c^2} H(r)...
Setup:
I'm trying to make the band structure for a planar photonic crystal with finite thickness, i.e., a quasi-3D problem.
I only want the x-direction band structure. So, I'm using variable floquet periodic BCs for the x-direction boundaries, and 0 degree floquet periodic BCs for the...
I've just read an article about IT with light instead of electrons:
http://focus.aps.org/story/v22/st15
I wonder, is there any indication that light processing will be faster than conventional electronics? Information transport is faster, but what about logic operations?
What would be...
Hi,
Can someone tell me how a wave is guided (in a fiber for instance) thinking
in term of diffraction (or scattering) and not in term of successive
reflections.
And my second question is : would it be possible to "extrude" a plan
diffractive element in a fiber to guide wave and have the...