Blazed gratings have excellent optical properties because they transmit the majority of the energy of the incident beam to a non-zero diffraction order, which facilitates spectral analysis and detection. They have a wide application in AR/VR and are fabricated by research institutes, IDMs and foundries. To further improve or optimize the reflectivity and the transmissivity, coating for blazed or anti-blazed face by different materials is important. For traditional deposition method, it is impossible to deposit different materials for each sidewall. The directional deposition of ion beam deposition (IBD) can achieve the deposition at a specific position. We make it possible to deposit various materials for each sidewall of blazed gratings. Leuven Instruments can provide a unique asymmetrical deposition method to help our customers achieve flexible deposition needs.