Hitachi diffraction gratings are products of technology accumulated in a span of over 30 years. The diffraction gratings capable of analyzing a variety of radiations ranging from soft X-Rays to far infrared are now expanding their application areas as optical elements, indispensable for spectroscopy.
The diffraction gratings developed by Hitachi have been used in various application areas and are now highly evaluated as the world's foremost element. Hitachi's highly reputed precision-ruling engine has now been combined with laser interferometric technology. This permits arranging the groves to a nanometer precision! Our burnishing technique, with use of a diamond tool, enables forming excellent grooves, making surfaces far smoother than vacuum evaporated metal surfaces.
Plane, Concave, or CUSTOM-designed diffraction gratings with a choice of blank material and coating:
Hitachi's highly reputed, precision ruling engine has now been combined with laser interferometric technology. This permits arranging the grooves to nanometer precision. Furthermore, a burnishing technique, making use of a diamond tool enables forming excellent grooves whose surfaces are far smoother than vacuum evaporated metal surfaces heretofore considered as the smoothest mirror surface. All these features serve to provide a highly efficient diffraction grating with minimum stray light in UV-VIS region as well as in the soft X-ray and vacuum UV regions. The accurate blaze angle and the regularly arranged groove-to-groove spacings can be observed clearly by scanning electron micrograph. This precision is shown in the figure to below.
The figure below shows a photograph of varied space grooves taken by using a scanning electron microscope. The spacing varies from 0.3 to 1.7µ in 50 nm increments.
Hitachi's new engine is capable of ruling varied-space grooves moreflexibly than the conventional engines. Common applications do not requiremuch varied spacing and do not require adjustment of tool loading. When a large space variation, such as shown above, is required, tool loading also need be adjusted.
This graph shows the efficiency of 1st-order diffraction light for each wavelength. Select a diffraction grating having an optimum blaze wave-length taking into account the energy distribution of the light source and the wavelength sensitivity of the detector to be used.
Part Number | Grooves per mm | Nominal 1st Order Littrow Blaze Wavelength | Blank Size H x W x T (mm) | Blaze Angle (degree) |
---|---|---|---|---|
001-0225 | 30 | 30,000 | 68.6 x 68.6 x 10 | 26.8 |
001-0226 | 66.6 | 3,000/10,000 | 68.6 x 68.6 x 10 | 5.7/19.3 |
001-0227 | 120 | 3,000/10,000 | 68.6 x 68.6 x 10 | 10.4/36.9 |
001-0228 | 300 | 6,000 | 68.6 x 68.6 x 10 | 21.1 |
001-0111 | 300 | 500 | 30 x 32 x 10 | 4.3 |
001-0126 | 300 | 500 | 58 x 58 x 10 | 4.3 |
001-0141 | 300 | 500 | 68.6 x 68.6 x 10 | 4.3 |
001-0156 | 300 | 500 | 65 x 76 x 16 | 4.3 |
001-0112 | 300 | 750 | 30 x 32 x 10 | 6.5 |
001-0127 | 300 | 750 | 58 x 58 x 10 | 6.5 |
001-0142 | 300 | 750 | 68.6 x 68.6 x 10 | 6.5 |
001-0157 | 300 | 750 | 65 x 76 x 16 | 6.5 |
001-0113 | 300 | 1,000 | 30 x 32 x 10 | 8.6 |
001-0128 | 300 | 1,000 | 58 x 58 x 10 | 8.6 |
001-0143 | 300 | 1,000 | 68.6 x 68.6 x 10 | 8.6 |
001-0158 | 300 | 1,000 | 65 x 76 x 16 | 8.6 |
001-0114 | 300 | 2,000 | 30 x 32 x 10 | 17.5 |
001-0129 | 300 | 2,000 | 58 x 58 x 10 | 17.5 |
001-0144 | 300 | 2,000 | 68.6 x 68.6 x 10 | 17.5 |
001-0159 | 300 | 2,000 | 65 x 76 x 16 | 17.5 |
001-0115 | 300 | 3,000 | 30 x 32 x 10 | 26.8 |
001-0130 | 300 | 3,000 | 58 x 58 x 10 | 26.8 |
001-0145 | 300 | 3,000 | 68.6 x 68.6 x 10 | 26.8 |
001-0160 | 300 | 3,000 | 65 x 76 x 16 | 26.8 |
001-0229 | 360 | 1,000 | 30 x 32 x 10 | 10.4 |
001-0116 | 600 | 200 | 30 x 32 x 10 | 3.4 |
001-0131 | 600 | 200 | 58 x 58 x 10 | 3.4 |
001-0146 | 600 | 200 | 68.6 x 68.6 x 10 | 3.4 |
001-0161 | 600 | 200 | 76 x 85 x 16 | 3.4 |
001-0117 | 600 | 250 | 30 x 32 x 10 | 4.3 |
001-0132 | 600 | 250 | 58 x 58 x 10 | 4.3 |
001-0147 | 600 | 250 | 68.6 x 68.6 x 10 | 4.3 |
001-0162 | 600 | 250 | 76 x 85 x 16 | 4.3 |
001-0118 | 600 | 300 | 30 x 32 x 10 | 5.2 |
001-0133 | 600 | 300 | 58 x 58 x 10 | 5.2 |
001-0148 | 600 | 300 | 68.6 x 68.6 x 10 | 5.2 |
001-0163 | 600 | 300 | 76 x 85 x 16 | 5.2 |
001-0119 | 600 | 500 | 30 x 32 x 10 | 8.6 |
001-0134 | 600 | 500 | 58 x 58 x 10 | 8.6 |
001-0149 | 600 | 500 | 68.6 x 68.6 x 10 | 8.6 |
001-0164 | 600 | 500 | 65 x 76 x 16 | 8.6 |
001-0120 | 600 | 750 | 30 x 32 x 10 | 13.0 |
001-0135 | 600 | 750 | 58 x 58 x 10 | 13.0 |
001-0150 | 600 | 600 | 68.6 x 68.6 x 10 | 13.0 |
001-0165 | 600 | 750 | 65 x 76 x 16 | 13.0 |
001-0230 | 600 | 950/1,900 | 30 x 32 x 10 | 16.6/34.8 |
001-0121 | 600 | 1,000 | 30 x 32 x 10 | 17.5 |
001-0136 | 600 | 1,000 | 58 x 58 x 10 | 17.5 |
001-0151 | 600 | 1,000 | 68.6 x 68.6 x 10 | 17.5 |
001-0166 | 600 | 1,000 | 65 x 76 x 16 | 17.5 |
001-0122 | 1,200 | 200 | 30 x 32 x 10 | 6.9 |
001-0137 | 1,200 | 200 | 58 x 58 x 10 | 6.9 |
001-0152 | 1,200 | 200 | 68.6 x 68.6 x 10 | 6.9 |
001-0167 | 1,200 | 200 | 65 x 76 x 16 | 6.9 |
001-0232 | 1,200 | 230 | 58 x 58 x 10 | 7.9 |
001-0123 | 1,200 | 250 | 30 x 32 x 10 | 8.6 |
001-0138 | 1,200 | 250 | 58 x 58 x 10 | 8.6 |
001-0153 | 1,200 | 250 | 68.6 x 68.6 x 10 | 8.6 |
001-0168 | 1,200 | 250 | 76 x 85 x 16 | 8.6 |
001-0233 | 1,200 | 250 | 150 x 150 x 25 | 8.6 |
001-0234 | 1,200 | 250/500 | 150 x 150 x 25 | 8.6/17.5 |
001-0124 | 1,200 | 300 | 30 x 32 x 10 | 10.4 |
001-0139 | 1,200 | 300 | 58 x 58 x 10 | 10.4 |
001-0154 | 1,200 | 300 | 68.6 x 68.6 x 10 | 10.4 |
001-0169 | 1,200 | 300 | 65 x 76 x 16 | 10.4 |
001-0125 | 1,200 | 500 | 30 x 32 x 10 | 17.5 |
001-0140 | 1,200 | 500 | 58 x 58 x 10 | 17.5 |
001-0155 | 1,200 | 500 | 68.6 x 68.6 x 10 | 17.5 |
001-0170 | 1,200 | 500 | 65 x 76 x 16 | 17.5 |
001-0235 | 1,440 | 230 | 30 x 32 x 10 | 9.5 |
001-0236 | 1,440 | 230 | 40 x 40 x 10 | 9.5 |
001-0237 | 1,800 | 200 | 68.6 x 68.6 x 10 | 10.4 |
001-0238 | 2,400 | 200 | 90 x 90 x 16 | 13.9 |
The variable spacing and curved groove ruling technology, developed solely by Hitachi, eliminates the aberrations inherent to the conventional concave diffraction gratings. This greatly enhances the spectral image focusing properties of concave gratings. The Hitachi aberration corrected concave diffraction gratings include high resolution, reduced astigmatism, compact size, etc., which can be selected in accordance with the function of the equipment to which they are applied.
The conventional concave grating images the spectra emitted from a pinhole into vertical straight lines, while the newly developed aberration-corrected concave grating images the spectrum in the form of a point.
Abberation correction by using the concave diffraction grating with varied-space grooves.
Abberation correction by using the concave diffraction grating with curved grooves.
Conventional (equally-spaced, straight grooves) concave diffraction grating.
T. Harada and T. Kita, "Mechanically ruled aberration-corrected concave gratings", Appl. Opt. 19, 3987-3993(1980).
From X-rays to Infrared! Gratings can now be designed to meet specific requirements
The diffraction gratings that are capable of analyzing a variety of radiations ranging from soft X-rays to far infrared are now expanding their application areas as optical elements, indispensable for spectroscopy.
Conventional Concave Gratings
Aberration-Corrected Concave Gratings
These gratings eliminate the coma-type aberration of the Seya-Namioka monochromator, which has been most widely used in monochromators with concave gratings that provide high resolution. Hitachi is manufacturing a wide variety of aberration-corrected gratings for Seya-Namioka monochromator which cover a wavelength range from the vacuum ultraviolet to the near infrared region.
These gratings are designed for normal incidence mounting. They reduce aberrations and at the same time increase the efficiency of light intensity. As a result, a high quality of image focusing of the concave grating is available.
Variable space grooves enable flat-field image focusing of concave grating spectrograph. The spectrograph permits simultaneous measurement of multi-wavelength spectra when combined with a linear array detector. These gratings are optimized for normal-incidence optical system (for VIS-UV ray).
Highly dispersive concave gratings for grazing-incidence mounting are available, especially for synchrotron radiation and extreme ultraviolet applications. These gratings are very effective for the application of soft X-rays whose reflectance is extremely low on a metal surface.
Diffraction gratings of special specifications can also be manufactured on request.
Pyrex glass is used as a standard material. Hitachi is also prepared to use materials other than Pyrex glass when specified.
Diffraction gratings are coated with aluminum (Al) as a standard. Hitachi will coat the gratings with gold (Au) and platinum (Pt) as special specifications.
Diffraction gratings with Part No. 001-0450 and 001-0437 exceptionally are coated with gold (Au) as a standard.
Diffraction gratings are overcoated with magnesium fluoride
(MgF2) or lithium fluoride (LiF) as special specifications.
Diffraction gratings are manufactured to dimensions other than specified in this catalog. They can also be shaped round.
For certifying the groove profile, an electron micrograph can be provided together with the manufactured diffraction grating at the expense of the customer.