Fig. 1. Device diagram of the microscopic SHG

Fig. 2. Relationship between the SHG intensity of BaTiO₃ and the square of incident light power

Fig. 3. SHG polarization diagram of the BaTiO₃

Fig. 4. Relationship between SHG signal intensity and light polarization angle under different polarization modes. (a) p-in; (b) s-in; (c) p-out; (d) s-out

Fig. 5. Relationship between the square of incident optical power and SHG signal intensity in different modes