Work

Topology optimization design of a TPMS-structured mirror for spaceborne high-energy laser beam expansion

Year: 2026

Type: article

Abstract: To meet the requirements for low thermally induced deformation and fundamental-frequency performance of the primary mirror in a spaceborne high-energy laser beam-expansion system, a topology optimization method is proposed for mirrors incorporating triply periodic minimal surface (TPMS) structures. Homogenization-based mappings were established between the unit-cell relative density and the effective mechanical and thermal properties. The square of the root mean square (RMS) value of the residual normal surface figure error after removal of the low-order terms was minimized subject to a first-natural-frequency constraint, using analytical sensitivities and a sequential quadratic programming (SQP) algorithm. Following explicit geometric reconstruction, the variable-density TPMS-structured mirror achieved a first natural frequency of 5188.20 Hz and an RMS of 20.16 nm. Compared with the uniform-density TPMS-structured mirror of the same structural mass, its RMS was reduced by 27.2%. Numerical results indicate that the proposed optimization method effectively improves the thermal surface figure stability of the mirror while satisfying the prescribed fundamental-frequency requirement.

Source: Optics Express

DOI: 10.1364/oe.613147