What is Spectroscopy: Definition and 332 Discussions

Spectroscopy is the study of the interaction between matter and electromagnetic radiation as a function of the wavelength or frequency of the radiation. In simpler terms, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum; indeed, historically, spectroscopy originated as the study of the wavelength dependence of the absorption by gas phase matter of visible light dispersed by a prism. Matter waves and acoustic waves can also be considered forms of radiative energy, and recently gravitational waves have been associated with a spectral signature in the context of the Laser Interferometer Gravitational-Wave Observatory (LIGO).
Spectroscopy, primarily in the electromagnetic spectrum, is a fundamental exploratory tool in the fields of physics, chemistry, and astronomy, allowing the composition, physical structure and electronic structure of matter to be investigated at the atomic, molecular and macro scale, and over astronomical distances. Important applications arise from biomedical spectroscopy in the areas of tissue analysis and medical imaging.

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  1. Hamidul

    MCNP code for Neutron Spectroscopy

    Hello everyone , in my mcnp coding for finding neutron spectroscopy I used F2 tally across a surface. Is it correct or I should use f4 tally? Morever I need to transform the flux data into neutron fluence. How can I do that. Here I uploaded my code. Though my data from codes is way more...
  2. Hamidul

    Help with neutron spectroscopy experiments in MCNP code

    Hello everyone, currently I am doing a neutron spectroscopy experiments. I am doing it with the MCNP code. I designed my Geometry there, but facing problems in data cards, is there anyone who can help me in this sector?
  3. Hak

    I Formation of emission lines and other topics

    If we spectroscopically observe a cloud of hot gas, which is on the whole not very absorbent, and which is not illuminated by a source behind it, we observe emission lines. How does this type of spectrum form? I had thought that those lines are those in which there are transitions of atoms is...
  4. starryexplorer

    I Obtaining Transit Spectrum for Celestial Bodies Using JWST NIRSPEC

    I've recently been tasked with obtaining transit spectrum data for some fascinating celestial bodies, including Ceres, Enceladus, Ganymede, Io, and Titan. The goal is to compare their transit spectra with that of Earth. However, I'm facing a bit of a challenge when it comes to using the Github...
  5. cemtu

    A Thomson - Rayleigh Scattering: Rotational & Vibrational Energy Levels

    We know from molecular spectroscopy that incoming light on a molecule can change a molecule's rotational, vibrational and electronic energy levels. If the incoming light is, on the far-infrared and microwave region the molecule gets rotational energy.(microwave spectra) on the near-infrared...
  6. P

    I Spectroscopy: vibronic and rotational transitions

    In spectroscopy, the highest peaks in the absorption spectrum are those that are associated with the most probable energy transitions in a molecule. The most probable transitions are those in which the best superposition between the wave function of the vibronic level of the fundamental state...
  7. tanaygupta2000

    Raman spectroscopy problem

    I know that for the vibrational Raman spectrum, the energy levels are given by- E(n) = ℏω(n+1/2) - χℏω(n+1/2)^2 But I'm not getting what does it meant by the Raman lines are observed at given values of wavelengths and the fundamental vibrational frequency. I equated the E(0) with the energy...
  8. Lotto

    B What do these wavenumbers correspond to in Raman spectroscopy?

    I don't know whether it is an energy of a photon emitted by a deexciting molecule, or if it is an energy of laser's photons. Here is an example of such spectrum: For example, that value of wavenumber ##3000\, \mathrm {cm^{-1}}## is an energy of an emitted photon or a photon from laser? And that...
  9. M

    A Nuclear moments in molecular spectroscopy

    Hello! I saw many paper extracting the magnetic dipole and electric quadrupole moments of the nuclei by performing RF/microwave spectroscopy on the rotational levels of a molecule. However, I can't seem to find paper measuring higher order moments. For example, the magnetic octupole moment has...
  10. S

    I Selection Rules for a Diatomic Molecule?

    Hello! I have a question about selection rules and electronic transitions of a diatomic molecule: I can't find a good explanation about that, and there's so much confusion about the right rules to use. I studied that on Bransden-Joachain's "Physics of atoms and molecules", but there (to whom...
  11. M

    I Absorption and emission spectroscopy of atoms

    Hello ! As I understand it, the different isotopes of the same atom have a slightly different spectroscopic absorption and emission where, for example, Deuterium absorbs slightly shorter wavelengths than Protium. My question is if two isotopes of different atoms, for example Tritium and Helium...
  12. L

    I How does atomic absorption spectroscopy work

    I did a prac where we tried to calculate the rydberg constant for hydrogen. We had a hydrogen lamp and we used a spectrometer that was hooked up to a photomultiplier tube to detect the wavelengths of light corresponding to the balmer series. In one section I need to write up a brief summary of...
  13. Salmone

    I Doubts about Fourier transform of IR spectroscopy

    I was studying a Michelson interferometer for infrared absorption in Fourier transform and I've found these two images (taken from https://pages.mtu.edu/~scarn/teaching/GE4250/ftir_lecture_slides.pdf ) representing an infrared monochromatic beam of light going into the interferometer and the...
  14. Supershandy

    I Help with Kubelka Munk equations in Excel

    Hello everyone. I'm trying to do a Kubelka Munk equation for paint samples and would like to do the calculation in Excel first before moving it over to a programming language outside of MATLAB. I have Spectroscopic scans of the samples and put them into a database where the K/S values have been...
  15. K

    A Fourier Transform MW spectroscopy in a FB cavity

    Hello! I am reading about Fourier Transform MW spectroscopy in a FB cavity, which seems to be quite an old technique and I want to make sure I got it right. As far as I understand, this is very similar to normal NRM, i.e. one applies a MW ##\pi/2## pulse which puts the molecules in a linear...
  16. A

    B Gamma spectroscopy, Compton edge

    Hello, I have a few uncertainties about this, Forgive the long questions, I appreciate your time. 1) Why is the maximum energy photon loses during Compton scattering about 0.238MeV (if maximum angle 180 achieved aka backscatter) irrespective of the incoming photon total energy? It seems...
  17. K

    I Quantum logic spectroscopy in a quadrupole trap

    Hello! I see that most experiments applying quantum computing techniques for high precision spectroscopy use a quadrupole trap. I don't know much about the experimental implementation of these kind of traps, so any help (or suggested paper) would be appreciated, but I was wondering how well can...
  18. R

    Interpretation of Net Peak Area in Gamma Spectroscopy

    Hello, My question relates to gamma spectroscopy. I understand how the net peak area is calculated for any photopeak. Fortunately, gamma-spec software (e.g., Genie-2000 from Canberra) provides Net peak area and associated uncertainty (for Cs-137 661.7 keV peak, as an example). My question: are...
  19. SJay16

    How would one estimate the rotation period of a star from its spectrum

    The figure is shown; the measurements were taken on two consecutive observing nights. The Ordinate is the flux normalized to continuum and the abscissa is the wavelength scale. You can see the "bumps" indicated by the arrows referring to some Starspot as the spot moves on the profile; assuming a...
  20. A

    I How do I properly plot the solar spectrum and handle the flux of Arcturus?

    I'm trying to plot the solar spectrum (Wavelength versus Flux) from a table of values I'm given. I'm given 3 columns; Solar Flux Arcturus Flux Wavelength Plotting Solar Flux versus Wavelength gives me a graph (below) that is very difficult to resolve. There are 21,000 data points as well. If...
  21. M

    I Ramsey spectroscopy and spin echoes

    Hello! Assuming we use a laser of frequency very close to resonance, in the Ramsey technique (say for 2 level atoms) the ##\pi/2## pulse would put the Bloch vector in the equatorial plane, along the y axis, then in the free region the vector will rotate around the z axis accumulating a phase of...
  22. F

    A Cross correlations with 2 probes: Approximation of a 2D + 3D synthesis

    I am interested, in the context of my work, in the cross correlations between a spectroscopic probe (which gives a 3D distribution of galaxies with redshifts, which is also called spectroscopic Galaxy clustering, GCsp) and a photometric probe (which gives an angular distribution, that is to say...
  23. mfb

    A Spectroscopy of positronium fine structure: 4.5 sigma deviation

    Precision Microwave Spectroscopy of the Positronium n=2 Fine Structure A nice compact abstract, so I'll just quote it here: Positronium with its two light leptons is the dream of every theorist, that keeps the uncertainties small. The 0.61 MHz experimental uncertainty are the sum of 0.57 MHz...
  24. D

    Quantum Help: Microwave Spectroscopy, C. H. Townes and A. L. Schawlow

    Hi, everyone: I tried to find the PDF or djvu for this book. Unfortunately, it failed to get it. Could you please so kind send me a link if you have? Thanks.
  25. M

    I Looking for introductory level reading on Rabi and Ramsey spectroscopy

    Hello! Can someone point me towards some introductory levels readings on Rabi and Ramsey spectroscopy. It seems that most readings online are scientific papers, I would like something more basic (e.g. lecture notes). Thank you!
  26. Ennio

    I Solar wind velocity and corrections

    Greetings, how do - the velocity distribution of the solar wind at 1 AU - the velocity distribution of the solar wind in our line of sight look like? I have found the 400 Km/sec but no further information. Is it an average values? Is this radially on the sun the same? Links with graphs are...
  27. A

    Wide-angle X-ray scattering (WAXS) spectroscopy

    I read the "J. Phys. Chem. B 2018, 122, 7616−7624" paper where they calculated the pair distribution function using wide-angle X-ray scattering and mentioned the term " The distances to the first coordination shell for low-, high-, and very-high-density amorphous ice (LDA, HDA, VHDA) were...
  28. K

    Best software to fit molecular spectroscopy data

    Hello! I have some data from a molecular spectroscopy experiment, containing vibrational and rotational spectra, and I want to fit the peaks with Voigt profiles (one for each peak) in order to obtain the centers of the peaks. Do you know any software suitable for this kind of fit? I usually use...
  29. N

    I Spectrometer vs Spectrometry vs Spectroscopy

    How do you differentiate between the three? I read that "Spectrometry deals with the measurement of a specific spectrum. There are four primary types of spectrometers: 1. Mass spectrometry 2. Neutron triple axis spectrometry 3. Ion-mobility spectrometry 4. Rutherford backscattering...
  30. marielescobal

    A Raman and X-ray Photoelectron Spectroscopy

    Summary: How can I know the effects of ions on my coating using Raman and XPS? Hi! So I'm working on my thesis regarding surface morphology of Zn doped HAp coating. Now, my goal is to know the effects of Zn ions on the surface morphology of my coating using raman and xps. Jowever, I do not...
  31. E

    A How to interpret N(E) vs. E graphs when performing Auger spectroscopy

    Hi all, my name's Ethan and I'm an undergraduate physics student conducting research on work functions this summer. I've been trying to understand the graphs of N(E) or N'(E) vs. auger electron energy for several days now, but I can't find in the literature what exactly N(E) or N'(E) are. I've...
  32. D

    I What optical filter to use for Raman spectroscopy?

    Raman spectroscopy involves Illuminating a target with a laser Beam. This produces Raleigh scattering. Does The releigh scattering have the same frequency as the laser beam? So use an optical filter to block the same frequency as the laser?
  33. M

    A Reviewing Spectral Imaging Techniques

    I am writing a review on snapshot spectral imaging techniques, and, being mainly interested in visible applications, I looked into spectral analysis with light field cameras, which have been rather popular in the previous years (see wikipedia): the main reference for these systems, at least for...
  34. D

    I Can Raman spectroscopy identify every substance?

    Can raman spectroscopy identify any substance or are there certain Substances raman spectroscopy cannot identify?
  35. A

    Studying Tips for learning spectroscopy

    Hi everyone! I'm a chemistry student, this year i have to learn different types os spectroscopy. I have had troubles to catch up with this subject. Would you please gimme some advices about sources of information to learn about spectroscopy? I Would appreciate it!
  36. phzrosmary

    A Raman spectroscopy and the phonon confined in the Brillouin zone

    Hello everyone, I need some confirmation on something: As far as I understood, the raman spectroscopy measures the inelastic scattering of a photon in a medium through the absorption or the emission of a phonon in the medium. The energy and the momentum is conserved...
  37. astroman707

    I What areas of nano/optical research applies to astrophysics?

    I'm an undergraduate and there is a very good optical spectroscopy and nano-materials physics lab at my college. I have FULL access to all equipment and a professor in that field is offering me a ridiculous amount of co-research time during the school year. However, I'm really only interested...
  38. G

    Problems with Raman Spectroscopy

    Hello, Recently I had a problem in the analysis of a raw material called Propranolol HCl, when performing Raman identification for the specific batch the obtained spectrum does not generate signal and, consequently, identity of the material. By testing other techniques like infrared and NMR, I...
  39. P

    Determine fine-structure constant

    Homework Statement The figure below shows the hyperfine structure in the transition 6s $^2S_{1/2}$ - 8p $^2P_{3/2}$ in 115In (I = 9/2). The measurement is made using a narrow-band tunable laser and a collimated atomic beam; hence the Doppler width is greatly reduced. The 6 components shown have...
  40. Wrichik Basu

    Chemistry Resources on UV-Visible Spectroscopy

    I need some good book(s) or other resources from where I can learn UV-Visible Spectroscopy. Besides explaining the mathematical and theoretical intricacies, it should also mention the practical aspects. If you have read any and found it good, please recommend it.
  41. Guilherme Franco

    A Little help interpreting spectral data from an article

    I'm trying to find a good database of absorption or reflection spectra in visible light for pigments. I've found a wonderful database in this article: http://e-conservation.org/issue-2/36-FORS-spectral-database#CSV It's almost exactly what I needed Except I don't understand the data The...
  42. Sophrosyne

    B Spectroscopy of Stars: Electrons in Plasma

    Astronomers can determine the presence various elements in a star through spectroscopy of the incoming light from that star. The characteristic spectral lines of each element are formed by electrons transitioning between the various orbital energy levels around the nucleus of their atom. But...
  43. Sophrosyne

    B Spectroscopy of clear gases

    To obtain spectroscopy on a gas like hydrogen or helium, an electric arc is passed through a container of the material, and then the emitted light is viewed through a prism which breaks it up into its component wavelengths. There are sharp lines which are formed, caused by excitation of the...
  44. Ella98

    UV-Vis spectroscopy: Changes in refractive index

    I wanted to know how do you control for changes in refractive index when you get the UV-Vis spectrum of an aqueous solution in a double beam spectrometer? Is that something the equipment does automatically? Or something I have to do? Also, how do these changes in refractive index occur? Thanks...
  45. T

    Beta Spectroscopy: Decay Path of Na 22 and Sr 90 | Experimental Setup & Results

    Homework Statement The decay path of Na 22 and Strontium 90 Experimental Setup The beta particle electron from strontium 90 and positron from sodium 22 physical measurement is as shown. Experimental Result (verified) Strontium beta particle(electron) Count Rate vs Energy(rest energy...
  46. P

    I Determining The Inclination Angle of A Stellar Binary System

    I am a Physics undergraduate at the University of Texas at Arlington. I am currently taking an Astrophysics class in which my professor talked about the inclination angle of the orbital plane of the binary star system and how it is impossible to determine that angle. I was wondering why is it...
  47. L

    Determining which energy level transfers cause peaks in x-ray spectra

    Hi all, I'm wondering how, for each peak in an x-ray spectra from a material (and using a crystal analyser), it is determined which energy level jump the peak corresponds to? How would you figure out the correct value of n to substitute into Bragg's Law to find the energy of the beam? Thank you!
  48. J

    A Oxygen 760nm spectroscopy - quick 'n' dirty

    'Morning all, I wish to use a 760nm laser to measure the concentration of molecular oxygen in a gas. I've a laser (multi-mode, not TDLAS:QLD-760-10S), a photodiode (Si), and I've built an oven to hold the laser diode at a constant temperature to avoid mode-hopping. Is it really as 'simple' as...
  49. Wrichik Basu

    Atomic Books on Ultrafast multi-dimensional coherent spectroscopy

    I am curious about Ultrafast multi-dimensional coherent spectroscopy and want to get a bit of in-depth knowledge on this topic. I've always been very interested in spectroscopy, much like my passion in quantum mechanics, though I don't get a lot of time after daily routine to study either...