It is demonstrated that the self-starting generation for a phase-conju
gate semilinear mirror is preceded by the silent zone, which is necess
ary for preparing a phase-conjugate generation structure in a multimod
e nonlinear resonator. The threshold for self-starting and the respons
e delay are calculated. The experiment with a strontium barium niobate
crystal demonstrates the reasonable quantitative agreement with the t
heory.