Product

Gratings can be classified into several different types according to the profile of the grooves. The respective features of three types of gratings manufactured by Shimadzu are described below.

1 . Blazed Holographic Gratings (BHG)

Sawtooth Grooves

• These gratings exhibit a high diffraction efficiency for specific wavelengths in a range from ultraviolet to visible light.
• The blaze wavelength (the wavelength corresponding to peak diffraction efficiency) is determined by the blaze angle.
• They can be used in spectroscopes for ultraviolet and visible light.

2 . Holographic Gratings (HG)

Sinusoidal Grooves

• These gratings offer a relatively high diffraction efficiency at a broad range of wavelengths.
• The wavelength corresponding to the peak diffraction efficiency is determined by the groove depth.
• In general, the diffraction efficiency is around half that of blazed holographic gratings(BHG) but the values of groove depth / period are large, it may be possible to obtain an efficiency greater than that of BHG.
• They are used for wide wavelength regions and the near infrared range.

3 . Laminar Gratings

Rectangular Grooves

• The diffraction efficiency for even orders of light is lower than that of BHG and HG.
• The wavelength corresponding to the peak diffraction efficiency is determined by the groove depth and the duty ratio (the width of the grooves with respect to the grating period).
• They are used in the soft X-ray region as a large reflectance can be attained in this region.