All Questions
36
questions
20
votes
4
answers
16k
views
"Lack of inversion symmetry" in crystal?
Apparently (first paragraph of this article) the lack of inversion symmetry is some crystals allows all sort of nonlinear optic phenomena.
Now. Does anyone know of an intuitive or just physical ...
- 24.9k
5
votes
0
answers
86
views
Simulation of a dispersive crystal mirror
I am trying to simulate a simple setup where I have a point source of broadband light whose light is incident upon a spherical crystal at a central angle $\theta_i$. Assuming Bragg diffraction some of ...
- 1,047
4
votes
1
answer
2k
views
Symmetry of the dielectric tensor
In the book Principles of Optics by Max Born, in chapter XIV, the rate of change in the electric energy density $w_{e}$ is generalised to
\begin{equation}
\frac{dw_{e}}{dt} = \frac{1}{4\pi}\sum_{kl}\,...
- 229
3
votes
2
answers
133
views
Why does "AT cut" of Quartz provide pure shear thickness oscillation?
According to this page https://www.nanoscience.com/techniques/quartz-crystal-microbalance/,
“AT cut” provides pure thickness shear mode oscillation where the two surfaces of the crystal move in ...
- 175
3
votes
1
answer
311
views
Focusing a Gaussian beam into a nonlinear crystal
Boyd analyzes in his book (Boyd's book), section 2.10.3, the case of harmonic generation using a focused Gaussian beam and he mentions that an analytic solution can be evaluated for certain special ...
- 135
3
votes
0
answers
338
views
Bandgap Spacing in Photonic Crystals
I am doing some self-study on photonics and have encountered the following question:
We know that amorphous electronic crystals such as amorphous silicon have a bandgap. Can amorphous photonic ...
- 283
2
votes
1
answer
2k
views
What is the relationship between directions in reciprocal and real space of a photonic crystal?
I am reading "Photonic crystals - molding the flow of light" by Joannopoulos et al. (available on-line). The figures below are reproduced from there.
This is a diagram of a triangular lattice of air ...
- 438
2
votes
1
answer
212
views
Laser induced damage in BBO crystal
Does the repetition rate [Hz] of a IR (1035 nm) pulsed laser play a role in the damage threshold of a BBO crystal?
- 21
2
votes
2
answers
109
views
Are there any crystallographic effects we can see in the reflection of visible light from metal surfaces?
I started thinking about this in a discussion in comments.
One can start by thinking of the reflection of visible light by most metals as similar to the reflection of radio waves in that it's an ...
- 6,273
2
votes
1
answer
99
views
Is the huge calcite birefringence accounted for by first principles?
The birefringence in calcite is huge (possibly the largest?). The question is, why is it so special? why is such kind of materials so rare?
In other words, is it explained by first principles?
By ...
- 231
2
votes
1
answer
97
views
Can polychromatic light be produced from monochromatic light after passing through a crystal in transmission spectroscopy?
I have an optical setup where monochromatic light (573.5nm) is passed through a cuprous oxide crystal (Cu2O). This light is then passed through a monochromator, but the output light is actually ...
- 21
2
votes
1
answer
105
views
Refractive Index Ellipsoid for Circular Birefringence Materials
When light travels through an anisotropic medium, its refraction may depend on both its polarization and propagation. Such materials may be classified in terms of their (Linear) Birefringence as ...
- 61
2
votes
0
answers
14
views
Atomic configuration along optic axis
How does the atomic configuration define a specific direction in a crystal called optic axis along which no birefrigence take place? What is so special about that particular axis ? What is the feature ...
1
vote
1
answer
266
views
Can you create high-energy photons using multiple low-energy photons? [duplicate]
I heard once that with a special crystal it's possible to "convert" somehow two green photons to a ultraviolet one and that some UV-lasers are based on this fact. Is this right, and even ...
- 125
1
vote
4
answers
945
views
How do we determine refractive index of a photonic crystal?
Normally, refractive index of a medium is defined as
$$n=\frac c{v_\text{p}},$$
where $c$ is the speed of light in vacuum, and $v_\text{p}$ is the phase speed of light in the medium. Phase speed is ...
- 29.1k