Diffraction Gratings for CS260B Monochromators

Compare	Model	Compatibility	rankScore	Type	Grooves per mm	Primary Wavelength Region	Blaze Wavelength	Peak Efficiency	Availability	Price	Brand
74061B CS260B Grating, Holographic, 1800 lines/mm, 500 nm blaze, 320-925 nm range $405 Contact Us	74061B CS260B Grating, Holographic, 1800 lines/mm, 500 nm blaze, 320-925 nm range	UNIVERSAL	1.0	Holographic	1800	Dual: 320-925 nm Quad: 320-785nm	500 nm	54%	Contact Us	$405	Oriel Instruments
74062B CS260B Grating, Holographic, 1201.6 lines/mm, 250 nm blaze, 200-600 nm range $405 Contact Us	74062B CS260B Grating, Holographic, 1201.6 lines/mm, 250 nm blaze, 200-600 nm range	UNIVERSAL	1.0	Holographic	1201.6	200-600 nm	250 nm	63% Efficiency at 200nm: 22%	Contact Us	$405	Oriel Instruments
74063B CS260B Grating, Ruled, 1200 lines/mm, 350 nm blaze, 200-1400 nm range $405 Contact Us	74063B CS260B Grating, Ruled, 1200 lines/mm, 350 nm blaze, 200-1400 nm range	UNIVERSAL	1.0	Ruled	1200	Dual: 200-1400 nm Quad: 200-1175 nm	350 nm	80%	Contact Us	$405	Oriel Instruments
74065B CS260B Grating, Ruled, 600 lines/mm, 200 nm blaze, 200-400 nm range $405 Contact Us	74065B CS260B Grating, Ruled, 600 lines/mm, 200 nm blaze, 200-400 nm range	UNIVERSAL	1.0	Ruled	600	200-400 nm	200 nm	60% Efficiency at 200nm: 21%	Contact Us	$405	Oriel Instruments
74068B CS260B Grating, Ruled, 600 lines/mm, 1200 nm blaze, 800-1900 nm range $405 Contact Us	74068B CS260B Grating, Ruled, 600 lines/mm, 1200 nm blaze, 800-1900 nm range	UNIVERSAL	1.0	Ruled	600	800-1900 nm	1200 nm	88%	Contact Us	$405	Oriel Instruments
74069B CS260B Grating, Ruled, 600 lines/mm, 1600 nm blaze, 875-2200 nm range $405 Contact Us	74069B CS260B Grating, Ruled, 600 lines/mm, 1600 nm blaze, 875-2200 nm range	UNIVERSAL	1.0	Ruled	600	875-2200 nm	1600 nm	85%	Contact Us	$405	Oriel Instruments
74070B CS260B Grating, Ruled, 400 lines/mm, 1200 nm blaze, 675-2500 nm range $405 Contact Us	74070B CS260B Grating, Ruled, 400 lines/mm, 1200 nm blaze, 675-2500 nm range	UNIVERSAL	1.0	Ruled	400	675-2500 nm	1200 nm	92%	Contact Us	$405	Oriel Instruments
74071B CS260B Grating, Ruled, 400 lines/mm, 1600 nm blaze, 925-2600 nm range $405 Contact Us	74071B CS260B Grating, Ruled, 400 lines/mm, 1600 nm blaze, 925-2600 nm range	UNIVERSAL	1.0	Ruled	400	925-2600 nm	1600 nm	82%	Contact Us	$405	Oriel Instruments
74072B CS260B Grating, Ruled, 300 lines/mm, 500 nm blaze, 300-1000 nm range $405 Contact Us	74072B CS260B Grating, Ruled, 300 lines/mm, 500 nm blaze, 300-1000 nm range	UNIVERSAL	1.0	Ruled	300	300-1000 nm	500 nm	80%	Contact Us	$405	Oriel Instruments
74073B CS260B Grating, Ruled, 300 lines/mm, 1000 nm blaze, 625-2000 nm range $405 Contact Us	74073B CS260B Grating, Ruled, 300 lines/mm, 1000 nm blaze, 625-2000 nm range	UNIVERSAL	1.0	Ruled	300	625-2000 nm	1000 nm	72%	Contact Us	$405	Oriel Instruments
74074B CS260B Grating, Ruled, 300 lines/mm, 2000 nm blaze, 1100-2400 nm range $405 Contact Us	74074B CS260B Grating, Ruled, 300 lines/mm, 2000 nm blaze, 1100-2400 nm range	UNIVERSAL	1.0	Ruled	300	1100-2400 nm	2000 nm	90%	Contact Us	$405	Oriel Instruments
74076B CS260B Grating, Ruled, 200 lines/mm, 1050 nm blaze, 580-1900 nm range $405 Contact Us	74076B CS260B Grating, Ruled, 200 lines/mm, 1050 nm blaze, 580-1900 nm range	UNIVERSAL	1.0	Ruled	200	580-1900 nm	1050 nm	85%	Contact Us	$405	Oriel Instruments
74077B CS260B Grating, Ruled, 150 lines/mm, 300 nm blaze, 200-650 nm range $405 Contact Us	74077B CS260B Grating, Ruled, 150 lines/mm, 300 nm blaze, 200-650 nm range	UNIVERSAL	1.0	Ruled	150	200-650 nm	300 nm	60% Efficiency at 200nm: 19%	Contact Us	$405	Oriel Instruments
74078B CS260B Grating, Ruled, 150 lines/mm, 800 nm blaze, 425-1750 nm range $405 Contact Us	74078B CS260B Grating, Ruled, 150 lines/mm, 800 nm blaze, 425-1750 nm range	UNIVERSAL	1.0	Ruled	150	425-1750 nm	800 nm	80%	Contact Us	$405	Oriel Instruments
74079B CS260B Grating, Ruled, 150 lines/mm, 1250 nm blaze, 820-2200 nm range $405 Contact Us	74079B CS260B Grating, Ruled, 150 lines/mm, 1250 nm blaze, 820-2200 nm range	UNIVERSAL	1.0	Ruled	150	820-2200 nm	1250 nm	85%	Contact Us	$405	Oriel Instruments
74080B CS260B Grating, Ruled, 150 lines/mm, 4000 nm blaze, 2500-12000 nm range $405 Contact Us	74080B CS260B Grating, Ruled, 150 lines/mm, 4000 nm blaze, 2500-12000 nm range	UNIVERSAL	1.0	Ruled	150	Dual: 2500-12000 nm Quad: 2500-9425 nm	4000 nm	88%	Contact Us	$405	Oriel Instruments
74082B CS260B Grating, Ruled, 75 lines/mm, 7000 nm blaze, 4500-20000 nm range $405 Contact Us	74082B CS260B Grating, Ruled, 75 lines/mm, 7000 nm blaze, 4500-20000 nm range	UNIVERSAL	1.0	Ruled	75	Dual: 4500-20000 nm Quad: 4500-18850 nm	7000 nm	80%	Contact Us	$405	Oriel Instruments
77958B CS260B Grating, Ruled, 1200 lines/mm, 500 nm blaze, 320-1100 nm range $405 Contact Us	77958B CS260B Grating, Ruled, 1200 lines/mm, 500 nm blaze, 320-1100 nm range	UNIVERSAL	1.0	Ruled	1200	320-1100 nm	500 nm	85%	Contact Us	$405	Oriel Instruments

Features

High Quality Richardson Diffraction Gratings

Plane ruled and holographic gratings listed here are fabricated from float glass substrates with an aluminum coating. The Oriel monochromators and spectrographs feature diffraction gratings produced by Richardson Gratings. Both Oriel Instruments and Richardson Gratings are part of the Newport family of brands, and have a long history of working together to design instruments that are appropriate for a wide variety of applications.

Selecting a Diffraction Grating

Diffraction gratings are primarily selected based on the spectral resolution requirements of the application and the spectral region of interest.

Spectral Resolution

Diffraction gratings are available in various groove densities (i.e. lines/mm). Higher groove densities give higher reciprocal dispersion and therefore higher resolution. The grating dispersion is similar for gratings with the same groove density. The exact dispersion is dependent upon other physical characteristics of the grating in addition to the groove density.

The resolution is the ability to separate wavelengths. It is usually expressed as the Full Width Half Maximum (FWHM). The resolution can be theoretically determined by multiplying the reciprocal dispersion of the grating by the slit width. The monochromator bandpass with a 1200 lines/mm grating is half that of the same arrangement with a 600 lines/mm grating. Note that this simple relationship is not accurate for slit widths below 50 µm, as the optical aberrations begin to play a role in the resolution.

Using a grating with a high groove density may increase resolution, but the spectral range narrows. The dispersion of a grating changes inversely with the groove density. If the groove density is halved, the dispersion is doubled. When performing a scan, to save time it is important to consider the resolution when determining the interval wavelength (i.e. the step size) of the scan. For example, if the resolution with a particular grating and slit is 5 nm, it is not necessary or practical to perform a scan every 1 nm.

Typical output power and resolution of various Oriel Tunable Light Sources, which utilize a Cornerstone 130 monochromator with extended range gratings. The slit width is set to 120 µm in the above illustration.

Spectral Region of Interest

The Blaze Wavelength is the wavelength for which a blazed diffraction grating is most efficient a diffracting monochromatic light into the first order. Choosing a blaze wavelength that is close to the spectral region of interest will allow for the highest possible efficiency.

High-efficiency gratings are desirable for several reasons. A grating with high efficiency is more useful than one with lower efficiency in measuring weak transition lines in optical spectra. A grating with high efficiency may allow the reflectivity and transmissivity specifications for the other components in the spectrometer to be relaxed. Moreover, higher diffracted energy may imply lower instrumental stray light due to other diffracted orders, as the total energy flow for a given wavelength leaving the grating is conserved (being equal to the energy flow incident on it minus any scattering and absorption).

Plane Ruled Diffraction Gratings

For a plane blazed grating, the groove spacing and blaze angle determine the distribution of energy. The blaze direction for most gratings is specified for first order Littrow use. In Littrow use, light is diffracted from the grating back toward the source. Gratings used in the Littrow configuration have the advantage of maximum efficiency, or blaze, at specific wavelengths.

Holographic Gratings

Holographic gratings normally have a sinusoidal groove shape, which is the result of recording interference fringe fields in photoresist material. Since the grooves are symmetrical, they do not have a preferred blaze direction and hence the gratings carry no blaze arrows. The range of useful diffraction efficiency is controlled by varying the modulation (the ratio of groove depth to groove spacing). The lower the modulation, the shorter the wavelength limit to which the grating can be used, but the peak efficiency may be lowered as well. We have found that three modulation levels are adequate for nearly all purposes.

Special Orders Welcome

In addition to the gratings listed here, special order gratings may also be available for use in a wide variety of applications. Custom grating requests include gold coating for increased IR efficiency, AlMgF₂ coating for increased UV efficiency and many other requests. Gratings may be installed into a variety of mounts for use in specific monochromators or spectrographs. Contact Newport Sales for more information.