Ultra-Low Linear Density Planar Diffraction Grating
Size: 20x20mm
Thickness: 2mm
Material: Float Glass
Wavelength Range:  200nm ~10000nm
Line Density  and Line Width
2Lines/mm  Line Width 0.5mm
4Lines/mm  Line Width 0.25mm
5Lines/mm  Line Width  0.2mm
8Lines/mm  Line Width  0.125mm
10 Lines/mm  Line Width 0.1mm
16 Lines/mm  Line Width 0.0625mm
20 Lines/mm  Line Width  0.05mm

Holographic grating:
The grating made by holographic technology uses the principle of optical coherent superposition. Simply speaking, by adjusting the complex term (time term), the peaks, peaks and valleys of the two optical wave trains are superimposed to achieve a high coherent field. Contrast technology.
Process:
The optically stable flat glass blank is coated with a layer of photoresist or other photosensitive material with a given thickness. When two coherent beams are generated by the laser to produce a series of uniform interference fringes on the coating, the photosensitive material is photosensitive. Then use special solvent to ablate the photosensitive part, that is, obtain a holographic image of interference fringes on the etched layer. The prepared diffraction grating; if a layer of aluminum reflective film is coated on the back of the glass blank, a reflective diffraction grating can be made.
The grating line groove manufactured by this method has high density and large scribing width, and the score line can reach 3663～4234 lines/mm, and the area can reach 165×320mm2.
The holographic grating has no ghost lines, and the stray light is small, which can eliminate the inherent shortcomings of the machine-engraved grating. Its actual resolving power can reach 80% to 100% of the theoretical resolving power.

Features:
a. No ghost line and companion line will be generated during work, which is the most popular among users.
b. There are no defects such as microscopic irregularities or burrs that mark the groove of the grating, so the stray light is much smaller than that of the grating.
c. The diffraction efficiency is low. The groove shape of the holographic grating is usually an approximate sinusoidal waveform. This groove shape does not have blaze conditions and has no obvious blaze characteristics. It is said that the holographic grating using the “ion etching” technology has greatly improved the diffraction efficiency of the grating.
d. High resolution. As the holographic technology greatly increases the total number of grating lines, the dispersion rate and resolution are also greatly improved.
e. Appropriately changing the production conditions can produce aberration-free holographic gratings.
f. Any size holographic grating can be made.
g. Short manufacturing cycle.