Diffraction Gratings for Oriel MS257 Monochromator and Imaging Spectrograph

Compare	Model	Compatibility	rankScore	Type	Blaze Wavelength	Primary Wavelength Region	Peak Efficiency	Grooves per mm	Availability	Price	Brand
77740 MS257 Grating, Ruled, 2400 lines/mm, 275 nm blaze, 200-700 nm range $1,025 Contact Us	77740 MS257 Grating, Ruled, 2400 lines/mm, 275 nm blaze, 200-700 nm range	UNIVERSAL	1.0	Ruled	275 nm	200-700 nm	69%	2400	Contact Us	$1,025	Oriel Instruments
77741 MS257 Grating, Holographic, 1200 lines/mm, 240 nm blaze, 200-600 nm $1,025 Contact Us	77741 MS257 Grating, Holographic, 1200 lines/mm, 240 nm blaze, 200-600 nm	UNIVERSAL	1.0	Holographic	240 nm	200-600 nm	63%	1200	Contact Us	$1,025	Oriel Instruments
77742 MS257 Grating, Ruled, 1200 lines/mm, 360 nm blaze, 200-1400 nm range $1,130 In Stock	77742 MS257 Grating, Ruled, 1200 lines/mm, 360 nm blaze, 200-1400 nm range	UNIVERSAL	1.0	Ruled	360 nm	200-1400 nm	80%	1200	In Stock	$1,130	Oriel Instruments
77743 MS257 Grating, Ruled, 600 lines/mm, 225 nm blaze, 200-400 nm range $1,025 Contact Us	77743 MS257 Grating, Ruled, 600 lines/mm, 225 nm blaze, 200-400 nm range	UNIVERSAL	1.0	Ruled	225 nm	200-400 nm	60%	600	Contact Us	$1,025	Oriel Instruments
77744 MS257 Grating, Ruled, 600 lines/mm, 370 nm blaze, 270-1000 nm range $1,130 Contact Us	77744 MS257 Grating, Ruled, 600 lines/mm, 370 nm blaze, 270-1000 nm range	UNIVERSAL	1.0	Ruled	370 nm	270-1000 nm	75%	600	Contact Us	$1,130	Oriel Instruments
77745 MS257 Grating, Ruled, 600 lines/mm, 1000 nm blaze, 650-2200 nm range $1,130 In Stock	77745 MS257 Grating, Ruled, 600 lines/mm, 1000 nm blaze, 650-2200 nm range	UNIVERSAL	1.0	Ruled	1000 nm	650-2200 nm	83%	600	In Stock	$1,130	Oriel Instruments
77748 MS257 Grating, Ruled, 300 lines/mm, 1700 nm blaze, 1100-2400 nm range $1,130 Contact Us	77748 MS257 Grating, Ruled, 300 lines/mm, 1700 nm blaze, 1100-2400 nm range	UNIVERSAL	1.0	Ruled	1700 nm	1100-2400 nm	90%	300	Contact Us	$1,130	Oriel Instruments
77749 MS257 Grating, Ruled, 200 lines/mm, 950 nm blaze, 580-1900 nm range $920 Contact Us	77749 MS257 Grating, Ruled, 200 lines/mm, 950 nm blaze, 580-1900 nm range	UNIVERSAL	1.0	Ruled	950 nm	580-1900 nm	85%	200	Contact Us	$920	Oriel Instruments
77750 MS257 Grating, Ruled, 150 lines/mm, 3500 nm blaze, 2500-11000 nm range $1,025 In Stock	77750 MS257 Grating, Ruled, 150 lines/mm, 3500 nm blaze, 2500-11000 nm range	UNIVERSAL	1.0	Ruled	3500 nm	2500-11000 nm	88%	150	In Stock	$1,025	Oriel Instruments
77751 MS257 Grating, Ruled, 75 lines/mm, 7 um blaze, 4.5-20 um range $1,025 Contact Us	77751 MS257 Grating, Ruled, 75 lines/mm, 7 um blaze, 4.5-20 um range	UNIVERSAL	1.0	Ruled	7000 nm	4500-20000 nm	80%	75	Contact Us	$1,025	Oriel Instruments
77752 MS257 Grating, Ruled, 1200 lines/mm, 750 nm blaze, 475-1400 nm range $1,025 Contact Us	77752 MS257 Grating, Ruled, 1200 lines/mm, 750 nm blaze, 475-1400 nm range	UNIVERSAL	1.0	Ruled	750 nm	475-1400 nm	78%	1200	Contact Us	$1,025	Oriel Instruments
77753 MS257 Grating, Holographic, 1800 lines/mm, 560 nm blaze, 320-925 nm $1,025 Contact Us	77753 MS257 Grating, Holographic, 1800 lines/mm, 560 nm blaze, 320-925 nm	UNIVERSAL	1.0	Holographic	560 nm	320-925 nm	54%	1800	Contact Us	$1,025	Oriel Instruments
77767 MS257 Grating, Ruled, 600 lines/mm, 1350 nm blaze, 800-1900 nm range $920 Contact Us	77767 MS257 Grating, Ruled, 600 lines/mm, 1350 nm blaze, 800-1900 nm range	UNIVERSAL	1.0	Ruled	1250 nm	800-1900 nm	88%	600	Contact Us	$920	Oriel Instruments
77768 MS257 Grating, Ruled, 600 lines/mm, 1325 nm blaze, 875 -2200 nm range $920 In Stock	77768 MS257 Grating, Ruled, 600 lines/mm, 1325 nm blaze, 875 -2200 nm range	UNIVERSAL	1.0	Ruled	1325 nm	875-2200 nm	85%	600	In Stock	$920	Oriel Instruments
77770 MS257 Grating, Ruled, 300 lines/mm, 950 nm blaze, 625-2000 nm range $920 Contact Us	77770 MS257 Grating, Ruled, 300 lines/mm, 950 nm blaze, 625-2000 nm range	UNIVERSAL	1.0	Ruled	950 nm	625-2000 nm	72%	300	Contact Us	$920	Oriel Instruments
77772 MS257 Grating, Ruled, 150 lines/mm, 300 nm blaze, 200-650 nm range $1,130 Contact Us	77772 MS257 Grating, Ruled, 150 lines/mm, 300 nm blaze, 200-650 nm range	UNIVERSAL	1.0	Ruled	300 nm	200-650 nm	60%	150	Contact Us	$1,130	Oriel Instruments
77773 MS257 Grating, Ruled, 150 lines/mm, 775 nm blaze, 425-1750 nm range $1,130 Contact Us	77773 MS257 Grating, Ruled, 150 lines/mm, 775 nm blaze, 425-1750 nm range	UNIVERSAL	1.0	Ruled	775 nm	425-1750 nm	80%	150	Contact Us	$1,130	Oriel Instruments
77774 MS257 Grating, Ruled, 150 lines/mm, 2500 nm blaze, 2500-3250 nm range $1,130 Contact Us	77774 MS257 Grating, Ruled, 150 lines/mm, 2500 nm blaze, 2500-3250 nm range	UNIVERSAL	1.0	Ruled	2500 nm	2500-3250 nm	32%	150	Contact Us	$1,130	Oriel Instruments
77984 MS257 Grating, Ruled, 1200 lines/mm, 500 nm blaze, 300-1100 nm range $820 In Stock	77984 MS257 Grating, Ruled, 1200 lines/mm, 500 nm blaze, 300-1100 nm range	UNIVERSAL	1.0	Ruled	500 nm	300-1100 nm	73%	1200	In Stock	$820	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.