May 25, 2017 | Detectors, Glossary of Spectroscopy Terms
Spectrometer Quantum efficiency describes how many photons that hit a detector actually generate electrons. It is usually expressed as a percentage of photons. It is also wavelength dependent. StellarNet provides detector efficiency curves that display this...
May 25, 2017 | Glossary of Spectroscopy Terms, StellarNet Definition
For clarity, “Dark” will be used to indicate a SpectraWiz dark spectrum and “dark spectrum” will refer to the concept. When you acquire a Dark, the SpectraWiz software saves the spectrum and subtracts it from all subsequent spectra that are acquired. Because of this...
May 25, 2017 | Glossary of Spectroscopy Terms, Spectroscopy, StellarNet Definition
The dark spectrum of a spectrometer is a spectrum taken with no light hitting the detector. It captures the shape of the baseline offset. It can be used to adjust sample spectra for non-uniformities in the detector pixels. The SpectraWiz software is able to do this...
May 25, 2017 | Detectors, Glossary of Spectroscopy Terms
Sometimes thermal fluctuations have enough energy to generate electrons in the same way that photons do. These electrons are not part of the signal, but there is no way to distinguish them from the signal in the detector, so they become a source of noise. The dark...
May 25, 2017 | Glossary of Spectroscopy Terms, Optics, Spectrograph
The f-number, also called the f-stop or the f-ratio, is an optical component’s focal length divided by its diameter: where N is the f-number, ƒ is the focal length, and D is the diameter. Often, this is written as “f/N,” so for N=4, it is written “f/4.” This number...