Observation of radiation pressure induced deformation of high-reflective reflector

In this paper, radiation pressure induced deformation of a series of thin aluminum reflectors is analyzed theoretically and experimentally. Theory of quantummechanics andmaterialmechanics are applied in 2D simulations and exhibits good coordinationwith experiment results. The original laser source used in the experiment is Gauss-distributed and has been shaped and expanded, resulting in theflattened light to avoid over heating or even ablation of the irradiated reflector, which can also bring amajor deformation. The aluminum reflectors are fabricated by a high precisionmachine tool into a thickness of 100, 200, 300 μmwith a surface roughness of 8 nm inRa, and then coatedwith high-reflective coatings andmounted on a thick 3Dprinting basemade of polylactic acid (PLA). In the experimental process, a vacuum chamber is employed to distinguish the effect of thermal convection. The results show that radiation pressure induced deformation has an obvious negative correlation with the reflector thickness. The time-deformation curve of the reflector reaches 2.4 μmpeak negative displacement atmost themoment laser beam is actingwhen under vacuum circumstance, and soon raises up to over 12 μmpositive displacement if the reflector is continuously irradiated. Subsequent analysis shows that such negative displacement is induced by radiation pressure and the positive displacement is caused by thermal expansion of the PLAbase.