From the special structure, processing technology and function of Fery prism in spectral imager, and the structural design features of a certain research spectral imager project, an assembly measurement method based on CMM, PSM and high precision rotating device is proposed, which combines the principles of space measurement, point source collimation and 3D mathematical modeling, the on-line inspection and alignment technology of Fery prism assembly are studied. Firstly, the key parameters of a single curved prism, such as curvature radius of surface, spherical coordinates, deflection angle of optical axis and off-axis are measured by CMM. Secondly, the Fery prism assembly is assembled by CMM, PSM and high precision rotating device. The space coordinates between the components are measured by CMM, and the position of the Spherical Center and the deflection angle are precisely determined by point source microscope. Finally, the actual assembly effect of the Fery Prism Assembly is reappeared through the data processing of the computer software, and the directional offset between the Fery prism assembly and the theoretical model is given, the precision assembly of Fery prism aseembly is completed by azimuth rotation and trimming mat processing. It provides a new technology method for on-line precision assembly of Fery prism module in Spectral Imager, which has strong operability and high measurement precision, and is suitable for precision detection and assembly of Fery prism module of different sizes.
In order to solve the image rotation in Sagnac transverse shearing interferometer, a model system is built on ray vector tracing and rotation matrix theory, as well as the theoretical imaging orientation and the actual imaging orientation with the angle error are demonstrated. Besides, the relation between the angle error and the rotation of the image body is concluded, which provides a theoretical guidance for optical alignment in Sagnac transverse shearing interferometer. Finally, an optimized optical alignment scheme is provided by the discussion of the angle error in the assembly and system-level loading process, which is also validated by optical alignment instance.