New opportunities of freeform gratings using diamond machining

With the recent development of new ultra fine aluminium alloys and progress in the field of directly machined freeform surfaces, diamond machined freeform gratings could play an important part in future spectrographs or integral field units, particularly at SWIR and LWIR wavelengths where the improved thermal performance of metal optics at cryogenic temperatures is well established. Freeform diamond machined gratings can offer a cost-effective, compact, and flexible alternative to gratings fabricated by other methods such as ion beam etching or complement these technologies. In this paper, both the advantages and limitations of 5 axis diamond machined freeform gratings are presented and potential applications are discussed