We present the latest developments at HORIBA of large size and high performances diffraction gratings for astronomy and space application. A new facility, called NANO-structure Larger Area Master (NANOLAM), has been built at HORIBA France SAS (Palaiseau, France), dedicated to the production of the largest gratings in the world.
This new facility allows us to design and produce very large gratings, in reflection or transmission with various possibilities of groove profiles and densities. From meter size pure holographic gratings up to 6000gr/mm on any substrate shape, to ion-etched transmission gratings competing favorably with VPH technology, HORIBA has developed the widest innovative diffraction gratings portfolio dedicated to astronomy application. The fused silica etched technology used to manufacture transmission gratings is unique and offer a number of consequent advantages over VPH technology such as a better wavefront, performances homogeneity or lifetime thanks to its bulky all glass material. This technology allows HORIBA to offer GRISMs (grating on a prism face) as well.
Apart from these exclusive holographic and ion-etched capabilities, HORIBA is also offering ruled gratings, generally dedicated to infrared spectral range with low groove densities. Echelle grating and immersed grating are also part of the HORIBA new capabilities.
In addition, HORIBA continues to develop another proprietary technology, the Variable Groove Depth (VGD) gratings that allows in a single grating a continuous blaze wavelength adjustment.
All the HORIBA gratings product range is cryogenic compatible, TRL9 space qualified and shows the best straylight performances on the market.
Finally, HORIBA is also currently performing several studies in partnership with laboratories and space agencies to further improve the state-of-the-art gratings straylight performances, as well as developing gratings on free-form surfaces.