  An attempt is made to present some experimental predictions of the
Randall-Sundrum model, where compactification radius of the extra dimension is
stabilized by the radion, which is a scalar field lighter than the graviton
Kaluza-Klein states. We calculate the conversion cross-sections of the photons
into the radions in the external electromagnetic fields, namely, in the static
fields and in a periodic field of the wave guide. Numerical evaluations of the
total cross-sections are also given. Our result shows that the conversion
cross-section in the static electric field is quite small. But, in the static
magnetic and periodic fields, the radion productions are much enhanced.
