Raman Definition and 90 Threads

What is the difference between Raman scattering and fluorescence emission?

I'm currently updating an old raman spectrometer that had fallen out of alignment requiring some modifications to its design. I have attached an image of what it currently looks like. I am using a HeNe laser which is directed into a bifurcated fiberoptic. The combined end is pointed at my...

Hi, I have been involved in a Raman Scattering project and have grasped the fundamentals of Raman Scattering. I'm no physics student, but rather a business student. 1. Can somebody explain to me why only a few protons scatter inelastically and not all of them? 2. Is there a method for...

Hi everybody, I am trying to learn how I can interpret the Raman spectra. How can we know which peak corresponds to which vibrational mode? We can find it by doing a simple literature scan that's ok but without literature scan, how can we know it? Is there any software? I did a basic...

Hi everyone, I have a project that will require me to use quite more Raman active dyes. I found a couple of dyes to start with but I couldn't find more that relate to material chemistry. Most of the literate that I read relates to proteins or DNA. Can you please think of some dyes that are...

Homework Statement The Raman spectrum of ethene, obtained using 488.0nm radiation from a laser, shows an intense line at 540.0nm. Calculate the wavenumber for this vibration I know that you get stokes, anti-stokes and rayleigh scattering. Not sure how to calculate the wavenumber though ...

Hello, I am currently in an analytical chemistry course where I am required to write a report on Raman Spectroscopy. The typical description of Raman Spectroscopy is the excitation of an electron to a "virtual" state, whereupon it can relax to a non zero vibrational level in its ground...

If the fluorescence is the re-emitting of a photon with a larger wave length due to the transition from a higher energy state to a lower energy state in the case of resonance Raman (where there aren't any virtual states) seems be equal to the fluorescence. Which differences are there?

hey guys, i hope you can help. my task is to analyse data of raman spectroscopy. therefor i have to deconvolute it. that means the data must have been convoluted somewhere. is it true that the raw data which i receive is convoluted already? or is it common to convolute the data "active"...

Hi all, I'm just wondering why pure metals, whatever kinds, do not have Raman peaks. Because the visible light cannot penetrate the metals? If so, what kind of EM wave can penetrate metals? Just need some key words for further information. Of course, I would appreciate if you would explain...

Regarding Rayleigh and Raman scattering: I'm trying to understand the implications of the Raman wavefunction, being time independent. It certainly makes the derivation of the resonance Raman cross-section simple, but I'm struggling to understand the role of the imaginary component...

I'm currently working on a lab that is exploring the Raman effect. One of the suggested exercises was to record the raman spectrum (from a mercury lamp through CCl4) around the rayleigh peaks at 435.8 nm and 404.7 nm. For the former, my results were fairly consistent with what I expected in that...

Tell me what do the peaks in the graph show which is b/w Intensity and wave number in raman spectroscopy ? Are the peaks due to transition from a grnd state to an exicted state or vice versa , low energy are stokes and high energy are the anti stokes one

RAMAN spectrum of iron oxide ! Dear every one! I have just got a new raman spectrometer to study the corosion of metals. i tested it on liquids (alcool, benzene, solvant ...) it works very well. i did also experiments on coal and carbon, perfect ! but when i tested on iron oxide .. i got no...

Hi How is it possible for a homogeneous molecule (i.e. one not having a permanent dipole moment and hence not IR active) to be Raman active? What my confusion is that since we cannot excite any states in the molecule (since it is IR inactive), then how can any scattering process even occur...

When you are setting up a spectral acquisition with a raman microscope, what does the exposure time mean? I would expect this to mean the amount of time the sample is exposed to the laser, but it doesn't seem like that can be true if it takes around 20 minutes to acquire the spectrum with a 2...

I am researching smart structures using optical fibre based sensors. One type used is distributed sensors of which there are two main kinds: ROTDR (Raman Optical time domain reflectometer) and BOTDR (Brillouin Optical time domain reflectometer). The former is based on Raman scattering within the...

Can one monitor dynamics of a specific protein domain (helix, strand etc) by Raman Sp? If one labels a specific residue with an isotope, like in NMR, can one use that to monitor the dynamics of the region that encompasses this residue?

Can someone qualitatively explain the difference between Raman scattering, Rayleigh scattering, and Brillouin Scattering with respect to molecules? I attempt to define each below but would appreciate either affirmation I'm correct or correction if I'm wrong. Raman scattering - Molecules...

can anyone explain what is d band and g band in the Raman spectrum of graphene?

I need certain clarifications in Raman effect. First of all, it is said that when a photon is incident on a liquid molecule, it gives part of its energy to the molecule, exciting it to the virtual level (higher one) and that the molecule when it returns not to the ground state from...

Please can anyone suggest a good book on raman spectroscopy. cheers.

Hi, For someone my question could be very simple but I couldn't find a well explain paper that explain this to me. In a Raman spectrometer the stokes and anti-stokes wavelength will always be grater than the laser wavelength used?. I have this confusion because I saw that Raman...

What are some simple graphs that can be created (in Matlab) relating to Raman Spectroscopy or just basic equations that can somehow be related to it? So far all I've done is graph E=E_0 cos (wt + 1/2 αt^2). And any suggestions of things I should read up on about the topic and understand...

Hello Group! I'm working on analyzing Raman spectra of proteins. I'm particularly interested in learning more about the signal processing of the amide I band. If anyone has any experience with Peakfit program or Origin, Savitsky-Golay smoothing, or amide I deconvolution for secondary...

I'm reviewing my scattering processes and can't quite pin down the difference between raman and compton... It sounds like Compton scattering is exactly the same as Raman scattering (with inverse-compton = raman stokes scattering; and normal compton = raman anti-stokes scattering). Also, just...

Homework Statement I understand that in the fluorescence, the incident photon is absorbed by the molecule, and the molecule while returning to its original ground level releases lesser energy. Similarly, in Raman effect also a photon is incident on a liquid molecule. In stokes' lines the...

I'm a freshman physics major and I'm doing summer research on Raman Spectroscopy. I've read up on it a bit but I was wondering if there are any resources that would help me better understand or at least get a general idea of what this is.

both rayleigh scattering and raman scattering are second order processes the difference is only that the final state of the atom/molecule coindices with the initial state of the atom/molecule in rayleigh scattering, while in raman scattering, the final state is different from the initial...

Hello Im doing som Raman spectroscopy of som substances. I know the signal/noise scales with the root of integrationtime. But can anyone tell me if averageing spectras gives any improvement in noise?

Raman spectroscopy of protein please help Hey any Raman experts out there? Im doing Raman spectroscopy of a protein called c-reactive protein (in aquous solution) using 532nm 10mW and the protein placed in a nmr tube. I can nicely get a spectrum of benzene and cyclohexane, but when I am doing...

I read in a journal article that in raman spectroscopy "it is well known that signal yield increases with shorter wavelength". Can anyone please explain why? I would've thought longer wavelengths = shorter frequencies = higher susceptibilities?

What's the best way to hold a sample of micron-sized polystyrene beads for raman microscopy?

What's the best way to hold a sample of micron-sized polystyrene beads for raman microscopy?

A raman scattered photon occurs when you drive the bonds of a molecule causing oscillations between the bonded molecules right? What exactly emits the photon? If its the electrons, then shouldn't multiple photons be emitted with the same wavelength?

Homework Statement For (NO)2+, experiments show 1 Raman active vibrational mode around 1450/cm; 2 strong IR active modes at 2400/cm and 550/cm; and 1 weak IR active mode around 3600/cm. What does that say about its geometry? The Attempt at a Solution Never mind, I think I got it :)

A laser in visible is used in Raman spectroscopy and the resultant spectrum is in IR and Microwave region(which means molecular vibrations and rotations are excited), what type of interaction is this that induces these levels? ( I cannot think more than..."To be Raman active molecules should...

Raman spectroscopy is "Single molecule identification" Hi , I heard that the speciality of Raman spectroscopy is "Single molecule identification", it'd be really great if somebody can tell me HOW! because its surely going to be a question in my exam! Thanks in advance.

Hi all, i am studying the physics of Raman Spectra. Was able to understand the origin of Vibrational Raman Spectra... which was an effect due to the change of polarizability with internuclear distance due to molecular vibration. But, i still yet to figure out why rotation of molecules can...

raman spectroscopy! Hi, can anybody please tell what is the speciality of Raman spectroscopy and how it differs from other techniques?? does it have any uniqueness? more info is welcomed! thanks in advance.