Fig. 1. Configuration of EM fields and axion field in the PIC code.

Fig. 2. Temporal evolution of axion field with different boundary conditions. Axion field distribution at different times with different boundary conditions: (a) reflection; (b) periodic; (c) outflow; (d) PML.

Fig. 3. Laser propagation and axion generation in a constant magnetic field. Distribution of normalized laser field ay=eEy/(meω0c) (upper half) and axion field (lower half) after propagating (a) 25 μm and (b) 89 μm. Comparison between the conversion probability from simulation result and theoretical prediction (c) P_γ→ϕ and (d) Pγ→ϕ during propagation.

Fig. 4. Axion conversion into EM fields. (a) and (b) Distributions of perturbed laser field E_y (upper half) and axion field (lower half) after propagating (a) 3 μm and (b) 96 μm. (c) and (d) Comparison between the conversion probabilities from the simulation result and the theoretical prediction: (c) P_ϕ→γ and (d) Pϕ→γ during propagation.

Fig. 5. Weak laser propagation and birefringence in a transversely magnetized plasma. (a) Distribution of laser magnetic field during propagation. (b) Comparison between laser group velocities from the simulation and theory. (c) Spatial distribution of the ordinary component E_1z and the extraordinary component E_1y in the birefringent effect. The electric field is normalized to E₀ = 10⁻²⁰cB_c. (d) Spatial Fourier transform of the ordinary component E_1z and the extraordinary component E_1y in the birefringent effect.