Lightnovo miniRaman Power 785nm: determining signal to noise ratio

This article describes the procedure of determining a signal to noise ratio of a Raman spectrometer on an example of Lightnovo ApS miniRaman Power 785nm spectrometer.

Raman spectrum of polystyrene was acquired with 785 nm laser of a Lightnovo ApS miniRaman Power spectrometer under following conditions: 250 ms exposure, 10 repetitions.

The signal level was estimated as the height of polystyrene 1001 cm-1 peak. The noise characteristics were estimated from the same spectrum in the spectral range 1700..2100 cm-1.

The baseline level was determined as the mean level of the signal in the range 1700..2100 cm-1.

baseline = noise_polystyrene["Intensity, %"].mean()        

The noise level was determined as a standard deviation of the signal in the range 1700..2100 cm-1.

noise = noise_polystyrene["Intensity, %"].std()        

The signal level was determined as the amplitude of the 1001 cm-1 minus baseline.

signal = signal_polystyrene["Intensity, %"].max() - baseline        

Signal to noise ratio was determined as follows:

SN_ratio = signal / noise        

The following values were obtained as a result of calculations:

baseline = 0.0543
noise = 0.0114
signal = 14.3540
SN_ratio = 1255.8572        

This gives signal to noise ratio of a miniRaman spectrometer as 1256:1 for an exposure time of 250 ms, 10 averages. Note that signal to noise ratio can be improved by increasing the exposure time and/or the number of repetitions.

As a conclusion, miniRaman offers excellent signal to noise ratio for a handheld spectrometer.

If you are interested in purchasing a miniRaman spectrometer or any other Raman spectrometer or microscope from our product line please contact us through our website https://lightnovo.com or send an email to [email protected]