Three Mirrors Aberrations Optical Transform Function with the Thermal Elastic Deformation

The field angle of TMA (three mirrors aberration) optical system is larger than coaxial optical system and more susceptible to the structure deformation. Thermal optical analysis is proposed for evaluating the optical MTF (module transform function). Temperature loads, such as X axial, Y axial and Z axial temperature gradients, are put on the optical system. The thermal elasticity deformations of reflector mirror surfaces made by frame deformation are computed. The deformations of reflector mirror surfaces are expressed in Zernike polynomial. With the optical design software optical MTF is computed. The results show that the X axial temperature gradient causes the MTF of optical system reduced furthest, the Y axial temperature gradient causes the minor MTF change, and the Z axial temperature gradient causes the least change of MTF. The research jobs could give some guidance and reference for the thermal design for TMA optical system.