Generation, Selection and Amplification of Mode-Locked Ruby Laser Pulses,

Abstract : A system capable of producing laser pulses of 5-20 picosecond duration and with energies of up to 40 mJ is described. The system consists of a TEM(oo)-mode, mode-locked ruby laser, an external pulse selector, and two amplifiers. TEM(oo)-mode operation is obtained in the passively mode-locked oscillator by the use of a ruby rod only 2.5 mm in diameter so that the rod is the limiting aperture of the cavity. The total pulse trains have energies of about 3 mJ, while individual pulses have energies of 0.2 to 0.3 mJ and are 20 to 25 psec in duration. The pulse duration can be reduced to approximately 5 psec by incorporating a telescope in the cavity. The probability of obtaining a cleanly locked pulse train exceeds 0.8 and intracavity damage is minimized due to the smooth mode profile. (Modified author abstract)