Topological nature of condensed matter has been receiving a long-lasting hectic interest. Among many topological types of materials, axion insulators are found to host many intriguing feature, such as quantized magnetoelectric coupling. This axion field also adds additional terms in the Maxwell equation, and is revolutionizing both materials science and physics. One of the main focuses is how to switch on different topological properties in an axion insulator, and previous works proposed that magnetic field and layer engineering could do such a work, in a well-known materials family MnBi₂Te₄. Recently, we predict that contactless and non-invasive light field could also realize an axion to quantum anomalous Hall state, according to Floquet band engineering. High Chern number arises depending on the stacking pattern of MnBi₂Te₄ and Bi₂Te₃. Interestingly, we reveal that nonmagnetic Bi₂Te₃ could host a large layer-resolved anomalous Hall conductance. These different states can be detected via measuring magneto-optical Kerr effect. See our recent publication in Nano Letters at https://pubs.acs.org/doi/abs/10.1021/acs.nanolett.4c01415.