However, when the signal linewidth is considerably narrower than the resolution of the spectrometer, the observed spectrum will be restricted by the spectrometer resolution. The effect can be ignored if the signal linewidth is considerably greater than the spectral resolution, and it can be assumed that the resolution measured is the same as the signal resolution.

Therefore, the observed resolution is the convolution of the two sources, It must be noted that the observed signal (S o) not only depends on the spectral resolution of the spectrometer (R), but also on the linewidth of the signal (S r). The detector determines the maximum size and number of discreet points in which the spectrum can be digitized the slit determines the minimum image size formed in the detector plane by the optical bench and the diffraction grating determines the total wavelength range of the spectrometer. In dispersive array spectrometers, three key factors determine the spectral resolution of a spectrometer: the detector, the slit, and the diffraction grating. For instance, if a spectrometer with a wavelength range of 200 nm possessed a spectral resolution of 1 nm, the system would be able to resolve a maximum of 200 individual wavelengths (peaks) across a spectrum.

A system’s spectral resolution determines the maximum number of spectral peaks that can be resolved by the spectrometer. Spectral (or optical) resolution is one of the most essential characteristics of a spectrometer.

Spectral resolution calculator