High performances diffraction gratings are usually key components for many scientific applications. Diffraction gratings are used in scientific studies to analyze, measure, propagate or tailor the light sources issued from nature, laser radiation or synchrotron radiation. The three main scientific applications we present are based on three different grating types: Laser Pulse Compression Gratings, Space Flight Gratings and XUV Synchrotron Gratings. These high performances diffraction gratings for scientific applications are designed and manufactured by HORIBA Jobin Yvon SAS (HJY part of HORIBA Scientific) at Longjumeau (France) in the Optical Components Division.