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inVia: sensitivity

inVia's design uses Renishaw's vast experience of precision and innovative engineering to make it the most sensitive Raman instrument available.

Its high sensitivity enables you to look at weak Raman signals. You can analyse minute traces of material, monolayers and weak scatterers.

Renishaw uses a stigmatic on-axis optical design in inVia. This provides high optical efficiency and excellent stray light rejection.

Optical efficiency

The small spot of Raman scattered light entering the spectrometer gives a sharp focused spot on the detector, rather than a blurred or elongated spot. This minimises the number of detector elements illuminated and maximises the signal-to-noise ratio (because each additional detector element used introduces more noise).

Excellent stray light rejection

Stray light within a spectrometer results in additional noise and inferior performance. inVia's design uses several techniques to reduce stray light:

  • the spectrometer uses a narrow entrance slit (between 10 µm and 65 µm) 
  • the optimised Rayleigh filter mount is positioned away from the entrance slit 
  • inVia's on-axis stigmatic design concentrates the signal to fewer detector elements, reducing the noise from stray light 
  • an internal cover isolates inVia's spectrometer from the rest of the instrument
  • it has a light-absorbing interior

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