Characterization - StellarNet, Inc.

What is broadband?

Apr 21, 2017 | Characterization, Glossary of Spectroscopy Terms

Broadband is an adjective used to describe light sources with a large wavelength range. While there is no clear cut numerical definition, hundreds of nanometers is usually called broadband. Many lamp sources, such as tungsten halogen lamps, are broadband. Lasers can...

What is a spectrometer’s System Sensitivity Curve?

Apr 21, 2017 | Characterization, Glossary of Spectroscopy Terms

The system sensitivity curve shows the total efficiency of the spectrometers. The total efficiency is a combination of the grating, detector, and optics. Below is a system sensitivity curve for a VIS BLUE-Wave spectrometer model: It was generated using a halogen lamp,...

What is Full Width at Half Maximum (FWHM)?

Apr 21, 2017 | Characterization, Glossary of Spectroscopy Terms

The full width at half maximum (FWHM) is the width of a line shape at half of its maximum amplitude, as shown below: A closely related quantity is the half width at half maximum (HWHM) or the Resolving Resolution and it is half of the FWHM. For Gaussian line shapes,...

What is Spectrometer Sensitivity?

Apr 18, 2017 | Characterization, Glossary of Spectroscopy Terms

There are many different definitions of sensitivity. For StellarNet, we use the word sensitivity to mean the total system response of a spectrometer versus wavelength. This is a combination of the detector response, grating response, and any loss due to optics....

What is Resolution?

Mar 21, 2017 | Characterization, Glossary of Spectroscopy Terms

Broadly speaking, resolution is the ability to detect differences in measured units. For spectroscopy experiments, the measured unit is the quantity used to describe the photon (e.g. wavelength, wavenumbers, frequency, energy). For example, if the resolution of an...

What is intensity of light?

Mar 19, 2017 | Characterization, Glossary of Spectroscopy Terms

When talking about light, intensity is the power per unit area when the light is transmitted through a (real or imaginary) flat surface that is perpendicular to the direction of the beam. It is usually represented by the symbol I and common units are W/m2 or W/cm2. At...