What is a Concave Grating?

Mar 19, 2017 | Glossary of Spectroscopy Terms, Spectrograph

Plane (flat) gratings are prone to coma and astigmatism. Using multiple optics, as in the Czerny-Turner configuration, also increases the stray light. To minimize these errors, the BLACK-Comet spectrometer uses a concave grating. This means the three optics in a...

What is a Czerny-Turner Configuration?

Mar 19, 2017 | Glossary of Spectroscopy Terms, Spectrograph

The Czerny-Turner configuration is a specific arrangement of optics in spectrographs. There are other configurations, but Czerny-Turner is the most common. A majority of StellarNet spectrometers use the Czerny-Turner configuration. The diagram below shows the...

What is an Chromatic Aberration?

Mar 19, 2017 | Glossary of Spectroscopy Terms, Properties of Light, Spectrograph

Chromatic aberration is an aberration caused by dispersion. When a beam of light is transmitted through a lens, dispersion causes the wavelengths to focus at different focal points. The aberration can be corrected by adding other materials to essentially cancel out...

What is an Aberration?

Mar 19, 2017 | Glossary of Spectroscopy Terms, Properties of Light, Spectrograph

What is an Aberration? An aberration is an optical imperfection that causes an optical system to deviate from its ideal performance. In a perfect optical system, all light rays would be focused exactly where intended. In practice, lenses, mirrors, and other optical...

What is Wavelength (Spectral) Range?

Mar 19, 2017 | Glossary of Spectroscopy Terms, Spectrograph

The wavelength range (also called spectral range) is the range of wavelengths that each spectrometer can measure. StellarNet offers spectrometer options that cover a 190-2500nm wavelength range. Wavelength range is based on the spectrometers grating’s ability...