Most spectrometers rely on a slit (aperture) to allow light to enter the instrument and reach the target sample. The size of the aperture affects throughput and resolution, with a narrow slit increasing resolution but decreasing signal strength. This typically presents a challenge for Raman measurements where signal strength is already a factor.
Our HES spectrometer range uses a fibre, typically of either 1 ml, 2 ml or 3 ml although up to 5ml is possible. Using a fibre aids transmission as the light that would normally be lost, particularly where a larger aperture is required, is retained. This makes the instrument significantly more sensitive to identifying Raman scatter.
As a result, our ultra-high-throughput/etendue HES spectrometers are ideal for Raman spectroscopy, capable of stand-off measurements at a range of 2 m – 3 m.