Raman Definition and 110 Threads

Hello everyone! I´m new to the forum and to start participating and being part of it I have the following problem and question: I began using a dispersive Raman system and I got spectra of Rhodamine B and heparin sodium (and anticoagulant and glycosaminoglycan) in solid form and the spectra...

Hi Does anyone know how Raman signal can be used in optoelectronic device fabrication?

I have a Optical trap that collects Raman. With Glass cover-slips we use a 1.51 refractice index oil (DF cargille). The trap works but glass has high auto-fluorescence at our excitation wavelength(785 nm9), the weak Raman can't be detected. So we use synthetic fused silica cover-slips with a...

Homework Statement The question states to identify which graph is associated with which molecule, which are CF4 and CF2Cl2. The graphs are measurements of infrared spectra, one has one peak while the other has two. It then asks to determine which symmetry labels are associated with each peak...

Dear friends I have a question regarding to polarized Raman spectroscopy. When we are talking about parallel and perpendicular electric field of the laser, is the magic angle 90° or 54.7°? I'd be grateful if you could answer me as soon as possible. Best wishes Kasra

Why we describe Raman modes At perticular wave number by E1 or A1,A2 or other If E1 say at 645cm-1, Why we cannot describe A1 at this wave number. How we write the representation at perticlar wave number. Please reply.

I have some raman data that I would like to prepare for inclusion in a report (and possibly publication in archival journal). The author guidelines for journals have not proven helpful in answering whether it is acceptable to perform data manipulations such as background subtraction. It has been...

Homework Statement The question relates to carbonic anhydrase with Zinc at the biosite. (1ca2 on protein data bank). Q: Why can you not study the water bound to the zinc when the molecule is in an aqueous solution? Homework Equations n/a The Attempt at a Solution I've had a...

When one calculate the real part of the index of refraction for a specific multilevel atom one would use the following formula: Re(n(\Delta))=1+\frac{N e^2}{8\pi \epsilon_0 m\omega} \sum_i \frac{\Delta_i}{\Delta_i^2+(\gamma/2)^2}K_i Where K_i is the C-G coefficient. My question is as...

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 I need help assigning the peaks in a Raman spectrum of acetylene(ethyne). The peaks are : Wavenumber Contours 3372 OQS 1973 OQS 613 OPRS 2. The attempt at a solution Ethyne has 7 vibrational modes (...

This was a quick short answer question from a previous final exam I'm studying from - the prof didn't provide an answer key. I can't think of any physical reason why this should happen. I can explain why the stokes/anti-stokes intensities vary with temperature, and why the linewidths vary...

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"...

I'm confused about what is going on theoretically with Raman, and light in general, wrt photon absorption, annihilation, and re-emission; I don't have the math background to understand Fourier transform, of anything past simple algebra anymore, but would like to at least have a decent...

I'm trying to understand how the polarization of an incident laser, (280.5 nm YAG in this case horizontally polarized) effects Vibrational Raman Scattering. Consider this laser incident on atmosphereic lab air (I'm seeing N2 and O2 stokes lines shifted to about 300nm) with a CCD lense's line of...

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...

Hello, I am looking for some expert advice from the community. I am preparating a planar SERS surface using polycrystalline gold as a substrate. It will be roughened with oxidation-reduction cycles. I want to measure the sers substrate enhancement factor (SSEF) using pyridine as a reporter. I...

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...

Hello everyone Lately I am taking some problem with my thesys, I am not an expert in theoretical physics but not bad as experimetal. I want to calculate the contribution of the w(q) away from zone O ob Brillouin to fit my experimental data to the theory and to know if the quantum theory work...

Hello everyone Lately I am taking some problem with my thesys, I am not an expert in theoretical physics but not bad as experimetal. I want to calculate the contribution of the w(q) away from zone O ob Brillouin to fit my experimental data to the theory and to know if the quantum theory work...

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...

Hello, My question is regarding sample preparation of biofilm for raman microscopy. In the past, I have used a Renishaw system 2000 raman spectrometer to study protein secondary structure. The sample preparation for this was fairly simple as I lyophilized the protein and placed it on a glass...

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...

Using a PMT/Monochromator, we have Surface Enchanced Raman Vials we are using to analyze samples. One thing I am trying to figure out: The so called finger print region is 500-3000 wavenumbers after the wavelength of the laser you are using. In our case, we are currently using a 200mW 532nm...

Hello everybody. I am designing a simple Raman spectrometer for student analysis. I have used 532nm DPSS 40mW Laser for this purpose. The sample i like to try now is liquid CCL4. In some pages, i have seen that CCL4 show raman spectrum in yellow light., i.e we can see yellow light comin...

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...