Spectrograph - StellarNet, Inc.

What is a dual blaze spectrometer grating?

Apr 21, 2017 | Glossary of Spectroscopy Terms, Optics, Spectrograph

A dual blaze grating is a grating with two blaze wavelengths. The SILVER-Nova Super Range spectrometer has a composite grating with a dual blaze at 250 and 1000 nm, giving it a wavelength range of 190-1110 nm. This can be seen in the grating efficiency curve: View...

What is a spectrometer’s Blaze Wavelength?

Apr 21, 2017 | Glossary of Spectroscopy Terms, Spectrograph

The blaze wavelength is the wavelength at which the grating is most efficient. Take a look at the grating efficiency curve for the UV BLUE-Wave spectrometer model: This grating is most efficient at 300 nm, so the blaze wavelength is 300 nm. This is determined mostly...

What is a spectrometer slit?

Apr 21, 2017 | Glossary of Spectroscopy Terms, Spectrograph

The slit is an opening that controls how much light enters the spectrometer. The width of the slit affects resolution; the narrower the slit, the higher the resolution. However, narrower slits also decrease signal strength. These two factors must be balanced when...

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...