All Questions
Tagged with optics spectroscopy
151
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36
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Calculating Bandgap of material from specular reflectance vs diffuse reflectance
I am looking for some clarification on whether specular reflection data can be used to calculate the bandgap of a material. I am using a UV-vis spectrometer and measuring the reflectance from an ...
- 421
1
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0
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22
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Understanding and researching with Spectroscopy
I am very new to physics so don't know a whole lot yet, so please correct any incorrect vocabulary you may find. Papers that are easy for beginners to understand are also very welcome!
Context:
I am ...
- 43
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52
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Ground state bleach in transient absorption with at least 3 states
The ground state (GS) bleach (B) is usually described by "less absorption due to depletion of electrons in the ground state". See here.
But the bleaching should also occur when there are ...
- 535
4
votes
1
answer
145
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About the focal length and $f\#$ of spectrometers
Suppose I image light into the entrance slit of a spectrometer (actually a monochromator).
The spectrometer is schematically shown below.
On the spectrometer's specs sheet, it is said that it has a ...
- 117
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38
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How to convert $\rm W/m2/sr/nm$ to $\rm kR/nm$ [duplicate]
How do I convert spectral radiance $\rm W/m2/sr/nm$ to $\rm kR/nm$?
I tried the following method from this paper: https://opg.optica.org/ao/abstract.cfm?URI=ao-13-9-2160
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83
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Converting $\rm W/m2/sr/nm$ to $\rm kR/nm$ for any wavelength
I have atmospheric spectra given in W/m2/sr/nm units and wavelength in nm. I want to convert W/m2/sr/nm to kilo Rayleigh/nm (kR/nm) for any wavelength.
I tried the following method from this paper: ...
- 11
2
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1
answer
35
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Advantage of a single large telescope over many small ones for optical/infrared spectroscopy?
In a thought experiment where we would like to do optical/infrared spectroscopy on distant galaxies, and in which we would like to increase as much as possible the resolution of the spectroscopy (...
- 1,109
9
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4
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560
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Getting the spectrum of light source at high intensity (for low transmittance measurement)
I am trying to measure the transmittance spectrum through a liquid sample using a visible-NIR spectroscopy (a spectrometer connected to a fiber optics and a collimating lens at the end), with tungsten-...
- 93
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55
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Is the Fourier Transform a reliable way to infer the physical phenomena producing an RF signal?
Consider the following thought experiments:
Scenario 1:
A person standing far away shines 3 light beams at you, each beam having a narrow spectral distribution centered around different frequencies F1,...
- 139
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1
answer
55
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Can I recover the physical wavelengths present in a light source from a time-series measurement of its amplitude?
Consider a mixture of different wavelengths being emitted from the same point (ex: a star). This light consists of a mixture of wavelengths and intensities at each wavelength. When measuring the ...
- 139
3
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2
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949
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Would the "FFT" of a light source be a reliable indicator of perceived color?
Paraphrasing from here:
A purely monochromatic 575nm wavelength light would be "perceived" as yellow, as would a light that has equal components in red and green (but no yellow). However, ...
- 139
1
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1
answer
106
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450nm peak absorption [closed]
I am looking for an oxide compound (metal oxide, or similar preferably inorganic) which shows light peak absorption at 450 nm. I have troubles in finding the right compound, as most of the oxides have ...
- 113
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29
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Absorbance spectrum of common metal oxides
I am looking into metal oxides particles, and I wonder where can I find the absorbance spectrum of visible light of common avaiable metal oxides?
- 113
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33
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Refractive index from absorbance, transmittance or reflectance spectra of thin film, knowing its thickness [duplicate]
I have absorbance (Abs), reflectance (R%) and transmittance (T%) data of TiO2 deposited thin film on FTO glass substrate. The data was collected using UV-Vis spectrophotometer. Also, I know the ...
- 11
2
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28
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Creating a wavelength selectable light source using diffraction grating and broad-spectrum led
Could a miniature wavelength selectable light source (lamp + monochromator) be created by using a broad spectrum led or tiny xenon/deuterium lamp as a light source combined with a small diffraction ...
