Lightnovo
Technical notes
Spectral Resolution Measurement According to ASTM E2529-06 (Calcite)
miniRaman Spectrometer & Spectral Resolution
- Compact & Lightweight – Dimensions: 112×39×34 mm³, Mass: 200 g.
- High Spectral Resolution – 6.5 cm⁻¹, measured using ASTM E2529-06 (2022).
- Patented Optical Design – High throughput (~92%) and reduced fluorescence impact.
- Versatile Applications – Suitable for field, benchtop, and integrated Raman spectroscopy.
- Measurement Procedure Using Calcite
- Optimizing measurement parameters (exposure time, number of repetitions).
- Aligning the sample for maximum Raman signal at ν = 1085 cm⁻¹.
- Recording the Raman spectrum and applying baseline correction.
- Fitting the data using an analytical curve to determine peak width.
- Calculating spectral resolution using the full width at half height (FWHH) of the ν = 1085 cm⁻¹ peak.
The measured spectral resolution was 6.53 cm⁻¹, confirming the capability of the miniRaman spectrometer for routine and process Raman applications. The method is simple, cost-effective, and can be performed in non-specialized environments without requiring dedicated calibration samples or service engineers
Lightnovo miniRaman spectrometer: Optimal profile for fitting of Raman peaks
The technical note focuses on accurate Raman peak fitting for data collected with our miniRaman spectrometers. This in-depth analysis helps users achieve more reliable results in Raman spectroscopy by identifying the most precise mathematical model for symmetric Raman peaks—a key step in material and chemical characterization.
This technical note is essential for researchers, lab analysts, and industry professionals looking to improve the accuracy of Raman data interpretation, especially when working with compact Raman instruments in the field or laboratory.
Key Takeaways from the Technical Note:
- Performance comparison of Raman peak fitting functions: Gaussian, Lorentzian, and Voigt profiles.
- Real-world application using a natural diamond sample measured with the miniRaman 785 nm spectrometer.
- Quantitative results based on Root Mean Square Error (RMSE) and Full Width at Half Height (FWHH).
- Voigt profile delivers the best peak fit, minimizing fitting errors and improving spectral analysis accuracy.
- Detailed explanation of spectral line broadening mechanisms: natural, collisional, and instrumental.
- Practical guidance for choosing the right Raman peak fitting method for miniRaman data.
Conclusion:
For users of portable Raman spectrometers, especially Lightnovo’s miniRaman series, the Voigt function is the most reliable profile for fitting symmetrical Raman peaks. It provides superior accuracy in determining peak position, width, and intensity—critical for applications in material science, forensic analysis, pharmaceutical quality control, and more.