The objective of the activity is the study and experimental verification of the feasibility of gratings machined on freeform surfaces.

Gratings are frequently used in optical instruments, e.g. spectrometers. Various production methods are available like etching using a hologram and ruling on high precision latches. Most techniques are typically used for a more or less symmetrical shape of the surface with the grating lines, like flat, cylindrical or spherical surfaces.The aim of the activity is to evaluate the feasibility of cost effective techniques for gratings not only limited to symmetrical surface shapes but also to be implanted on so called freeform surfaces.Furthermore there is a growing need to accurately specify the shape of the lines (or grooves) in order to optimize the efficiency and wavelength positioning of the diffracted light.A possible solution could imply the use of high accuracy single point diamond turning machines. Alternative solutions could be based on holographic techniques.The availability for designers of this freeform grating production technique enables a more compact design of optical configurations and may reduce the number of components in a design, resulting in lower weights and costs of optical instruments.For the proposed optimisation a study needs to be conducted with theoretical and experimental investigations.The study shall include a survey of different manufacturing techniques. A baseline method shall be identified based on at least the following criteria:- Possibility to use freeform surfaces as grating substrates- Possibility to generate arbitrary groove curves- Costs and reliability of the manufacturing process- Grating straylight- Grating efficiency After selection, the proposed technique shall be used to produce a grating prototype.