Compare Model Drawings, CAD & Specs Type Grooves per mm Blaze Wavelength Peak Efficiency Primary Wavelength Region Availability Price
$650
In Stock
Holographic 1200 240 nm 63% 200 to 600 nm
In Stock
$417
In Stock
Ruled 1200 360 nm 80% 200 to 1000 nm
In Stock
$402
In Stock
Ruled 600 1000 nm 83% 650 to 2000 nm
In Stock
$391
Ruled 300 1700 nm 90% 1100 to 2400 nm
$402
In Stock
Ruled 150 1850 nm 88% 1450 to 2200 nm
In Stock
$393
Ruled 75 8000 nm 80% 4.5 to 20 µm
$383
Ruled 50 12000 nm 80% 7 to 23 µm
$378.01
Ruled 600 225 nm 60% 200 to 400 nm
Ruled 600 700 nm 78% 450 to 2000 nm
Ruled 1200 750 nm 78% 475 to 1000 nm
$650
Ruled 2400 275 nm 69% 200 to 500 nm
$587
Holographic 1800 560 nm 54% 320 to 670 nm
$587
Holographic 3600 300 nm 60% 250 to 330 nm
Ruled 150 800 nm 80% 425 to 1600 nm

Features

High Quality

Plane ruled and holographic gratings listed here are fabricated from float glass substrates with an aluminum coating. 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.

Easy Installation

These 30 x 30 mm gratings come pre-aligned in their own frames, allowing them to precisely fit inside the instrument. The frame has a tab that allows the grating to be inserted or replaced inside the monochromator without touching its surface. Each grating comes with a protective cover and is labeled with the model number, making interchangeability and storage simple. Note that the instrument will need to be recalibrated after replacing the grating.

Plane Ruled 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.

Broad Wavelength Coverage

Standard grating assemblies are available from UV, VIS and NIR. The primary wavelength region is where the grating efficiency is greater than or equal to 20%. System efficiency will also be affected by the reflectivity of the mirrors and the grating angle, at any wavelength. The 77250 monochromator's gratings are available with operating ranges from 200 nm to 23 µm.

Blazed 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.

High 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).

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.