Calculator Input
Use any supported mode to calculate Raman shift, scattered wavelength, or excitation wavelength. The result appears above this form after submission.
Plotly Graph
The graph shows how scattered wavelength changes with Raman shift for the current excitation wavelength. Stokes and anti-Stokes branches are plotted together.
Example Data Table
These sample values illustrate common spectroscopy scenarios and help verify the calculator behavior.
| Example | Excitation (nm) | Scattered (nm) | Transition | Raman Shift (cm-1) |
|---|---|---|---|---|
| Silicon-like peak | 532.00 | 547.14 | Stokes | 520.13 |
| Benzene-like band | 532.00 | 561.92 | Stokes | 1000.86 |
| Graphitic anti-Stokes | 633.00 | 575.38 | Anti-Stokes | 1582.03 |
| Carbon-like D band | 785.00 | 878.05 | Stokes | 1349.98 |
Formula Used
Raman calculations are usually handled in wavenumber units. The calculator converts wavelength to wavenumber first, performs the shift operation, and converts back when needed.
Stokes lines appear at longer wavelengths and lower photon energy than the excitation beam. Anti-Stokes lines appear at shorter wavelengths and higher photon energy.
How to Use This Calculator
- Select the calculation mode based on the value you want to find.
- Choose the transition type for shift-based calculations.
- Enter excitation wavelength, scattered wavelength, or Raman shift as required.
- Choose nm or µm for each wavelength field.
- Click the calculate button to display the result above the form.
- Review the detailed output table, graph, and summary metrics.
- Use the CSV or PDF buttons to export the result.
FAQs
1. What is Raman shift?
Raman shift is the difference between excitation and scattered light expressed in cm-1. It represents molecular or lattice vibrational information and is commonly used to identify materials and analyze chemical structure.
2. What is the difference between Stokes and anti-Stokes lines?
Stokes lines occur when scattered photons lose energy, so wavelength increases. Anti-Stokes lines occur when scattered photons gain energy, so wavelength decreases. Both provide vibrational information, but anti-Stokes signals are often weaker.
3. Why is Raman shift usually written in cm-1?
Wavenumber is convenient because it scales directly with photon energy differences in spectroscopy. It also makes peak comparison easier across instruments using different laser wavelengths.
4. Can I use micrometers instead of nanometers?
Yes. The calculator accepts both nm and µm for excitation and scattered wavelengths. It converts values internally, then calculates the Raman shift and related outputs consistently.
5. Why do I get a nonphysical result warning?
That usually means the entered shift is too large for the selected wavelength and transition type, causing a negative or zero wavenumber. Review the input values and confirm the correct branch.
6. Does wavelength change linearly with Raman shift?
No. Raman shift is linear in wavenumber space, not wavelength space. Because wavelength and wavenumber are inversely related, the wavelength response becomes nonlinear as shift changes.
7. Can this tool help estimate photon energy changes?
Yes. The output includes excitation and scattered photon energies in electronvolts and also reports frequency shift in terahertz for additional spectroscopy interpretation.
8. What does the graph show?
The graph plots scattered wavelength versus Raman shift for both Stokes and anti-Stokes branches at the current excitation wavelength. If a result exists, the calculated point is highlighted for quick checking.