Single axial mode operation of aQ-switched Nd:YAG oscillator by injection seeding

We have achieved stable Fourier transform limited single axial mode operation of an unstable resonator Nd:YAG oscillator by injection seeding of an external signal. A detailed theoretical and experimental treatment of axial mode selection via injection seeding is presented. Our study shows that the axial mode selection process in
Q
-switched lasers via injection seeding is quite different from the frequency locking in CW lasers via injection locking.