Diode-pumped solid body laser comprises an acoustic-optical modulator, a laser crystal, a delay plate and a crystal that doubles the frequency of the laser beam. Pulse lengthening is carried out by internal coupling of a doubler mechanism within the laser resonator Preferred Features: The end surface of the laser crystal is formed as an end mirror limiting the laser resonator. The mirror is highly reflective for the laser beam. Crystals of SiO2 or TeO2 are provided for the acoustic-optical modulator.