Holographic Grating

The holographic grating is formed by the interference of two interfering laser beams to form fringes, and is exposed on a polished negative, and a sinusoidal pattern is formed on the exposure medium. Holographic gratings are specially designed to reduce or eliminate the effects of blazed gratings caused by periodic errors, such as ghost images (or ghost lines), relatively more stray light, and so on. The holographic grating is not easy to produce blaze, and the efficiency is lower compared with the ruled grating. But when the ratio of scribed width to wavelength is close to 1, the efficiency of holographic gratings is virtually the same as that of scribed gratings. Furthermore, a holographic grating with 1800 lines per millimeter is as efficient as a ruled grating at 500 nm. Can be used in spectrometers, spectrophotometers, and monochromators. This product is aluminized and has great reflectivity in the ultraviolet, visible and infrared spectral ranges.