Questions tagged [optical-materials]
The optical-materials tag has no usage guidance.
285 questions
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Is there super-transmissivity?
I have little knowledge about quantum phenomena, but I have read about super-conductivity and super-fluidity. The first involves zero resistance and the second involves zero viscosity. I suddenly ...
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Why grating is an essential part of a monochromator?
From looking at these two images, it appears that the dispersed "rays" of the reflected light could be manipulated just as well if the reflecting mirror would be turned to a fixed angle. So why is ...
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Optical Waveguide's "Base Bandwidth"
Consider a dielectric slab waveguide (lossless, isotropic) illuminated transversally from the vacuum (with coherent, monochromatic light).
We define the base bandwidth of a waveguide (or optical ...
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Why air spacing for high power beam splitters?
Ordinary glass cube beam splitters are constructed with a dielectric or hybrid coating on the hypotenuse of a right angle prism which is then cemented to another right angle prism. These fail in ...
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Where to find known dielectric functions of materials?
I've done a lot of experimental work in materials science and solid-state physics, but I'm currently venturing into the computational realm. I'm trying to compute optical constants ($n$ and $k$) for a ...
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Optical signal filters
Are there any optical filters which filter the signal's frequency and not based on the wavelength of the light? So what I mean is, if I have a modulated/pulsating light signal riding on a large DC ...
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Identifying diagrams for optical processes
I was reading some papers on the study of the optical properties of some metals and came upon these conference proceedings by Hopfield from 1972. They are on the study of the infrared properties of ...
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optical scattering cross section and polarization tensor
The optical scattering and absorption cross sections are well known to be
$$
C_{sca} = \frac{k^4}{6\pi}|\alpha|^2 \qquad C_{abs} = k\Im (\alpha)
$$
where $k$ is the wavevector and $\alpha$ is the ...
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Can you burn invisible jelly balls with a laser?
Suppose you have some jelly balls with similar refractive index as that of water, like in this video.
You put them in water, making it invisible. So, the optical behavior of the balls should be ...
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How do "see through mirrors" work? [duplicate]
(I called them see through mirrors because I don't know what their actual name is)
I have seen a lot of pictures of glass-like materials which reflect light from on side, and from the other side, ...
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Why does (oxidized) aluminum have a diffuse optical appearance?
Unoxidized aluminum has a shiny appearance like typical metals. However in air aluminum rapidly oxidizes, giving it a more diffuse appearance (or bidirectional reflectance distribution function). ...
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Nonlinear Optics: SHG and OPO
I am new to nonlinear optics, and recently I started studying about the second harmonic generation (SHG) and the optical parametric oscillation (OPO) where these two nonlinear interactions are ...
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Metamaterial : Snell's law and Fermat principle
How do we deduce Snell's law using Fermat's principal in case of metamaterials? Metamaterials have negative refractive index. This makes the refracted ray of light bend on same side of normal as ...
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What is so special about calcite that it has double refraction?
In this video is explained how the double refraction occurs. But it explains that if the ordinairy ray is horizontal and the extraordinairy is vertical that the first one gets less delayed than the ...
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Plasma frequency
I have a neutral plasma and I need to solve Maxwell equations given the charge and current densities on the plasma. In order to do it I need to know the electrical permittivity $\varepsilon$, I've ...
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Optics, What is a Foil?
I was using a program for simulating optical elements; mirrors, gratings, foils, crystals, slits, and zoneplates are what it mentioned. Does anyone know what a foil is in terms of optics? I know what ...
user24082
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How can fiber optic image conduits consist of only fiber core, no cladding?
Looking at fiber optic image conduits, I found that they have a packing fraction (the ratio of the fiber core's area to the total area) of 100% (source here).
In other words, they consist only of ...
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Temperature-induced wavelength shift of optical coatings?
Optical coatings designed for reflection or anti-reflection are made of many thin layers which will expand when heated. What will the effect be on the wavelengths the coating will reflect when the ...
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Why does light either get reflected, absorbed, or passes through a surface or obstacle?
For each of these 3 cases, I'm having trouble understanding...
If light is reflected, does that mean that there was not sufficient energy by the photons to excite the electrons of the surface to ...
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Focal plane of ideal thin lenses and spherical mirrors
Recently I was studying about optical instruments and in my book I came across a point which stated that
When non axial parallel rays are incident on an ideal spherical mirror at a small angle or a ...
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Why is this laser beam being scattered(and not)?
I was shining a laser beam through a liquid filled test tube(an ester particularly),and I found this phenomenon rather intriguing.Have a look.
Now when I passed the laser straight through the upper ...
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Why is GaN better than Si as a substrate for ZnO thin film?
in an attempt to grow a thin film using ZnO, I found many researches use silicon as a substrate and others use GaN. by further research I found that GaN is preferred than silicon but I don't know the ...
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An object's colour and its relation to light
I know that an object (say, a block of red colour) appears red because white light from the light bulb or sun shines on it, and the block absorbs all the other wavelengths of light except that ...
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How to control the refractive index of semiconductors?
I keep seeing/hearing that the refractive index can be controlled in semiconductors, but every time I read something like that it's always something very specific, like "Refractive index ...
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Is there such a material that only emits, or "sends out" the same color light that was "taken in" (absorbed)?
For example, glow-in-the-dark materials (photoluminescent) only emit a green hue regardless of the color of the light shone on the material.
Is there such a material that emits the color of the light ...
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See through material for IR camera
I have an IR camera that I'm trying to hide behind an opaque or fine meshed material (plastic?).
Any idea?
Thanks!
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What are some liquids with high ranges of refractive index with change in temperature?
I need to run an experiment on the effect of temperature on refractive index of a liquid, and in order to make the change most visible and have the lowest percent uncertainty I need the change in ...
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Why can't we create a laser with wavelength of 13.5nm?
I was reading about EUV and the extraordinary process of firing two different lasers as tin droplet to collect 13.5nm wavelength light and I was wondering why this is required and we can't just create ...
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What is difference between Electromagnetically induced transparency (EIT) and Coherent population trapping (CPT)?
EIT: Electromagnetically induced transparency
CPT: Coherent population trapping
When two resonant light fields (probe field and strong coupling field) are incident on an opaque material whose atoms ...
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How to figure out TM and TE modes based on dispersion relation?
According to this paper (https://doi.org/10.1063/1.5128679), the dispersion relation of hyperbolic materials is as follows:
then it is said, that he first term in brackets in the equation describes a ...
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What can be the possible causes for variation in stress-induced birefringence in an isotropic material?
Birefringence is the phenomenon of a material having a refractive index that depends on the polarization and propagation direction of light. When an unpolarized light passes through such a material, ...
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What determines the penetration of electromagnetic waves?
What is it that determines whether or not an electromagnetic wave can penetrate different materials and how far it can go? For example light can penetrate through glass, but not concrete walls, but ...
user284476
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How the optical CD disc gets drawn in when we gently push it? what is the mechanism behind it? [closed]
We have seen CD drives that have slits. The CD gets drawn inside upon a gentle
push. how the CD gets drawn inside upon a gentle push? How it's mechanism works?
user271982
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Is magneto-optic Kerr effect discernible for material with natural optical activity?
Magneto-optic Kerr effect requires a system with internal magnetism or external magnetic field and exhibits, say, circular dichroism for reflection measurements. Natural optical activity can have ...
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How to decide between sizes of particles for maximum light intensity for scintillation?
Are nanoparticles or microparticles or quantum dots better suited as scintillation materials as far as light yield intensity is concerned? I was unable to find literature that compares micro vs ...
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Bandwidth-length product of an optical fiber
A multimode step index fiber has a numerical aperture of 0.2 and a core refractive index of 1.47 . Estimate the bandwidth-length product for the fiber assuming only intermodal dispersion when:
(a): ...
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How can the speed of light in matter be measured?
Experiments such as Focault's measure speed of light in matter. Focault's experimental set-up is based on the idea that it takes more time for light to travel through matter, which will result in the ...
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Magnifying power of a microscope for a farsighted person
I was doing some problems on optical instruments and in one of the questions it was asked that if a simple microscope(magnifying glass) has a magnifying power 5X for a normal relaxed eye.. what will ...
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What does the refractive index for e.g. alpha mean?
When I look for some materials like https://en.wikipedia.org/wiki/Barium_sulfate and want to extract the refractive index then there is written: (nD)=1.636 (alpha). And sometimes also for beta and ...
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Properties of light and refractive index of materials
Why does the refractive index of a material dependent on the wavelenght of light incident on it.
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Can a mirror reflect only one color while allowing all other visible light pass through?
Is it possible to construct a mirror such that it only reflects certain wavelengths of visible light while allowing other wavelengths of visible light to pass through? I was reading about microwave ...
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Minimum seperation between two Airy disks as a function of the distance between two point sources of coherent light passing through the same objective
I have two coherent point sources of light, $A$ and $B$, separated by a distance $L$, which I focus down to the diffraction limit using a high-powered objective (e.g. a $\approx 100x$ objective). If ...
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Microscopic origin of non-linear optical effect
I know that a non linear optical medium is a medium in which the optical response for example polarisation vector varies as
\begin{equation}
\vec{P}=\epsilon_0\chi^{(1)}\vec{E}+\epsilon_0\chi^{(2)}\...
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How thin can a layer be in a multilayer and still act as a reflection interface?
Assume a multilayer with high and low refractive index layers. Now imagine that the high refractive index layers are successively made thinner and thinner. At what point would a single layer no longer ...
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Is it possible to have an optical version of a greenhouse? With optical fibers?
Optical fibers transport light within them using internal reflection, but the light only enters from one end of the fiber. Is it possible to somehow have light entering from the sides of the fiber (...
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Visible light through a single-mode optical fiber?
If I understand things correctly, the optical fibers used for (long-range) data transmissions are generally single-mode fibers, transmitting light in the 1300-1500 nm spectrum.
Now, could such a ...
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Why are things reflective, absorbent, transparent etc? [duplicate]
What determines whether a material reflects, absorbs or transmits a certain wavelength of light? Just a layman's question.
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Size of metal domain needed to reflect light ; are small graphene sheets shiny?
I remembered that shininess of a material is because of reflection, ie surface current responding to light. Mathematically, one can solve Maxwell equations under a relevant boundary condition, with ...
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Non-dispersive mediums for light
Apart from the vacuum are there other mediums for which light velocity does not depend on frequency?
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Obtaining both relative permittivity and permeability from refractive index
The complex refractive index $\tilde{n}$ is related to the relative electric permittivity and the magnetic permeability with the relation
\begin{equation}
\tilde{n} = n + \mathrm{i} k= \sqrt{\...
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