Ocean Optics - Inventor of the World's First Miniature Spectrometer

Choosing a Spectrometer Grating:
for the NIRQuest Series of Spectrometers

You choose from 2 gratings for each NIRQuest Optical Bench spectrometer. With each grating, you consider its groove density (which helps determine the resolution), its spectral range (which helps determine the wavelength range) and its blaze wavelength (which helps determine the most efficient range).

Performance and Stability

Instead of the gratings rotating as they do in instruments such as scanning monochromators, our gratings are permanently fixed in place at the time of manufacture to ensure long-term performance and stability. (Gratings can only be changed at the factory.) A grating must be specified for each spectrometer channel.

Grating Selection Charts

The charts below allows you -- with the help of our Applications Scientists -- to select the best grating for your application requirements.

NIRQuest Gratings for Preconfigured Setups

Spectrometer	Standard Grating	Groove Density (lines/mm)	Spectral Range	Blaze Wavelength	Best Efficiency (>30%)
NIRQuest512	NIR3	150	~800 nm	1100 nm	900-1700 nm
NIRQuest512-2.2	NIR2	100	~800 nm	1100 nm	900-2050 nm
NIRQuest256-2.1	NIR2	100	1150 nm	1600 nm	900-2050 nm
NIRQuest256-2.5	NIR1	75	1425 nm	1700 nm	1075-2500 nm

NIRQuest Gratings - All Options

Grating	Intended Use	Groove Density (lines/mm)	Spectral Range*	Blaze Wavelength	Best Efficiency(>30%)
NIR1	NIRQuest256-2.5	75	1600 nm	1700 nm	1075-2500 nm
NIR2	NIRQuest512-2.2 NIRQuest256-2.1, NIRQuest256-2.5	100	1200 nm	1600 nm	900-2050 nm
NIR3	NIRQuest512, NIRQuest512-2.2 NIRQuest256-2.1, NIRQuest256-2.5	150	~800 nm	1100 nm	900-1700 nm
NIR10	NIRQuest512, NIRQuest512-2.2 NIRQuest256-2.1, NIRQuest256-2.5	300	350-380 nm	1200 nm	750-2200 nm
NIR11	NIRQuest512, NIRQuest512-2.2 NIRQuest256-2.1, NIRQuest256-2.5	400	240-290 nm	1600 nm	980-2500 nm
NIR12	NIRQuest512, NIRQuest512-2.2 NIRQuest256-2.1, NIRQuest256-2.5	500	160-220 nm	1370 nm	900-2500 nm
NIR13	NIRQuest512, NIRQuest512-2.2 NIRQuest256-2.1, NIRQuest256-2.5	600	100-180 nm	1200 nm	800-2500 nm
NIR14	NIRQuest512	1000	50-90 nm	1310 nm	900-1700 nm
Additional grating options, adjustments to starting and ending wavelengths and similar customization may be available. Please contact an Applications Scientist for details.

* For optimum performance, we recommend setting the starting wavelength no lower than 900 nm unless absolutely necessary.

To see the efficiency curve of a specific grating, and to compare similar gratings, click on the Grating # in the far left column of the table above.

Groove Density. The Groove Density (mm^-1) of a grating determines its dispersion. The greater the groove density, the better the optical resolution possible, but the more truncated the spectral range.
Spectral Range. The dispersion of the grating across the linear array; also expressed as the "size" of the spectra on the array. When selecting gratings, you must choose a wavelength range with a width equal to the Spectral Range entry in the Spectrometer Grating Selection Chart. The grating's highest efficiency is within the range listed in the Best Efficiency (>30%) column.
Blaze Wavelength. The peak wavelength in the typical efficiency curve for a ruled grating. Also, for a holographic grating, the most efficient wavelength region.
Best Efficiency ( >30%). All ruled or holographically etched gratings optimize first-order spectra at certain wavelength regions; the "best" or "most efficient" region is the range where efficiency is >30%. In some cases, gratings have a greater spectral range than is efficiently diffracted.

.

HOME	PRODUCTS	SERVICES	TECHNICAL	APPLICATIONS	CORPORATE	DISTRIBUTORS	CATALOG	NEWSLETTER	CONTACT
. Copyright 1989 - 2010 Ocean Optics, Inc. All rights reserved. Terms of Use and Privacy Statement +1 727.733.2447 • +1 Fax 727.733.3962 •

Choosing a Spectrometer Grating: for the NIRQuest Series of Spectrometers

Performance and Stability

Grating Selection Charts

Choosing a Spectrometer Grating:
for the NIRQuest Series of Spectrometers