A new approach for tunable subnanosecond pulse generation using an active mirror: theoretical and experimental study

We report a simple technique for generation oftunable subnanosecond pulses (0. 1-0.3 ns) based on single spike selection from the relaxation oscillations in a dye laser by use of an active mirror. The selection is in original two-wavelength cavity with competitive generations at two wavelengths, the second of which is forced in appropriate moment by the quickly included amplification of the active mirror to suppress the initially started lasing in the first channel. To produce such switching we form the pump pulse by temporal division of a 15-50 ns standard pump laser pulse using a Pockel's cell with a 1-2 us switching time and an optical delay line. We have shown that in addition, such formation increases essentially the selected spike power. The proposed technique widens the choice of suitable lasers in which the single spike selection tecluiique may be applied to include dye lasers excited by a Q-switched solid-state laser or a Cu-vapor laser. The other advantages in comparison with the given in the literature single-spike selection techniques is the improved reproducibility of the selection for high ( 100-200 %) pump pulse power fluctuations, shorter pulse duration and pulse shape improvement. Both theoretical consideration and experimental verification are carried out