12
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Why are spectrums of incandescent light bulbs continuous despite the presence of Argon around them?
Seeing thin absorption lines is difficult. You need pretty good equipment to see them over an extended body. If you're just looking at it with a prism, it will overlap enough that such lines are ...
- 42.3k
3
votes
What is the difference between the dipole in IR and Raman vibrations?
Both IR absorption/Rayleigh scattering and Raman scattering involve oscillating electric moment of molecules. But just because there is Raman scattering, and therefore electric moment oscillates, it ...
- 41.2k
2
votes
Decoding the character table
Looking at page 81 and 82 of Applications of Group Theory To the Physics of Solids. by A. Dresselhaus it seems that the second last column are the possible basis functions of that irreducible ...
- 8,499
2
votes
Accepted
Baseline correction algorithm for Raman spectra. Raman baseline removal
For each abscissa, read off the numerical values for the ordinates of the two plots and pair them - the first value from your spectrum as $x$ and the value from the P Cygni data as $y$.
Now load ...
- 89.3k
2
votes
Lorentz distribution in emission peaks
The Lorentzian line shape arises when the width of the peak is determined by homogeneous broadening. It isn't an arbitrary choice by overzealous curve fitters, that really is the expected shape of the ...
- 363k
2
votes
Accepted
Classical treatment of Raman effect
In this basic classical treatment, you will always get Raman scattering, whether you send in a modulated or DC field. But in reality, all of the details come from the innocuous-looking "oscillator ...
- 12.2k
2
votes
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How does Raman scattering not break energy quantization?
Like any good quantum mechanical phenomenon, Raman scattering admits both a wave picture and a particle picture. You might not like either of them, though.
As far as the photon picture goes, it's ...
- 135k
2
votes
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Laser flux power density and Raman scattered radiation
Well, sorry for the short answer, but "laser flux power density" is just $I_0$, which is the power per unit surface area (which is why it is called flux power density) and the Raman intensity is ...
- 4,200
2
votes
The typical IR spectrometer broadband source emits all IR frequencies of interest simultaneously
There are two possible routes to making a broadband light source.
Incoherent sources
The first way is to make a source that emits light at a bunch of different frequencies without any coherence ...
- 135k
2
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Accepted
The typical IR spectrometer broadband source emits all IR frequencies of interest simultaneously
Thermal emission (often idealized as blackbody radiation) is broadband, i.e. emitting multiple frequencies at once. An incandescent lightbulb is like this. The references provided in the question make ...
- 6,674
2
votes
Accepted
Complex dielectric function and normal reflectance
Let me take you through deriving the boundary conditions. I had a fantastic Prof, who explained this very well. We can derive them by evaluating some of Maxwell's equations at the interface.
...
- 511
2
votes
Accepted
How to determine if a calculated Raman mode in a crystal is active or not?
In principle you should determine the irreducible representation of the mode, i.e. how its eigenvector transforms under the symmetry operation of the space group, and look up whether the irreducible ...
- 1,273
2
votes
Accepted
Are virtual states eigenstates of physical observables?
The wikipedia page called "virtual state" is too brief to be useful. The problem is that it does not ever define what it means by a virtual state.
I think the term "virtual state" ...
- 61.8k
1
vote
Accepted
450nm peak absorption
Try cerium doped scintillation crystals made from gadolinium aluminum gallium garnet, see https://www.nature.com/articles/s41598-020-77451-x.
In metal oxides, the valence band is primarily composed of ...
- 215
1
vote
Real part of Raman response function in linear response theory?
This can be understood on general grounds through the theory of linear response. In Raman scattering and many other cases, we're typically interested in the response of a Hermitian operator to a real-...
- 2,749
1
vote
Accepted
Raman scattering collection geometry
I will answer this question from the perspective of the Raman scattering experimentalist with the condensed matter background.
These are, indeed, most popular geometries with backscattering one being ...
- 61
1
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What's the difference between inelastic X-rays scattering and Raman scattering?
Raman Scattering is indeed an inelastic scattering process. Raman scattering is synonymous to inelastic scattering of photons.
Raman scattering is usually done in IR region, the reason being ...
- 1,082
1
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Why are spectrums of incandescent light bulbs continuous despite the presence of Argon around them?
For the argon inside a light bulb to affect the passage of light through it in a measurable way, it needs to be hot enough to be ionized. Then it will begin absorbing and emitting its characteristic ...
- 97.8k
1
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Why are spectrums of incandescent light bulbs continuous despite the presence of Argon around them?
Sure, argon absorbs some light at its favorite wavelengths. It probably does create some tiny dips in the lamp spectrum - and off my head I am sure there is no that much precise measurement technique ...
- 8,249
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How to explain about Raman spectroscopy?
Raman spectroscopy is an instance of inelastic scattering of light by molecules in the lattice.
Suppose the lattice was in some particular vibrational and rotational state. When light is incident on ...
- 891
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Selection rules in spectroscopy
The way light interacts with atoms can be modelled by the electron cloud responding to the EM field of light. The response for low intensity light is predominantly dipolar. The dipole operator is odd ...
- 9,463
1
vote
Constrained Brilloiun zone sum to integral
Why do you have to begin with a switch to an integral? You could simply expand your initial sum using the properties of $\delta$ as
$$S=\sum_{\vec{k}_1,\vec{k}_2}{|\Delta_{\vec{k}_1}|^2|\Delta_{\vec{...
- 29.6k
1
vote
Molecular Rotational energies and frequencies of diatomic molecule
You can treat this classically if you consider your diatomic molecule as a rigid rotor. The classical rotational energy is expressed in terms of the angular momentum $J$
$$
E_{rot} = \frac{1}{2} \...
- 321
1
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Raman vs Fluorescence, scattering vs absorption, classical vs quantum
The main difference between the two is the time scale, as you've already discussed a bit in your question. The other main Physical difference is that fluorescence is the result of relaxation from an ...
- 11
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Phonon scattering process in raman spectroscopy
Just to add some more notes to Steve's response:
This process only involves one $D$ phonon, which has energy approx 1335 cm${}^{-1}$ and is located at a Kohn anomaly at the $K$-point of the Brillouin ...
- 61
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