The prime objective of the grating machine is to provide a fabrication technology of unusually large size stitchingless, high spatial coherence gratings with moderat cost versus size increase.
The basis of the linear unit is a stable hard stone plate finely lapped of highest precision. The upper surface of the base plate shows 2 notches. The first one is used to guarantee highest precision in straightness translation and minimal yaw deviation in horizontal X axis direction by air bearings. In the second notch, the motorization by ironless linear motor is realized. The system is placed on adjustable membrane air springs, which insulate the system from influences by vibration.
The linear X axis is made of a stable, fine lapped hard stone plate with specifically designed vacuum-air bearings of highest stability. This part builds the carriage for the grating substrate in size from A3 to A0. Two ultra-precise optical zerodur glass scales are used for system positioning. In addition, the glass scales also detect the yaw deviation. This error can optionally be tilted by real time compensation.
The portal brace is also made of fine lapped hard stone in order to avoid the effects of different material pairing. It builds the support for the 1D phase-mask scanner which can be adjusted in height.