Passive high energy Q-switched laser system with optically synchronized multi-stage/multi-pass amplification

A sub-nanosecond laser system comprising:

• a pump laser source operable to generate a pump laser beam having a pump wavelength;
• a first pump beam splitter operable to receive the pump laser beam and split the pump laser beam into at least a first split pump laser beam and a second split pump laser beam;
• a passively Q-switched seed laser operable to receive the first split pump laser beam and generate a seed laser beam, the passively Q-switched seed laser comprising a cavity comprising a gain medium and a passive attenuator;
• and
• an amplifier assembly operable to receive the second split pump laser beam and the seed laser beam and generate an amplified laser beam, the amplifier assembly comprising one or more amplifiers, wherein the one or more amplifiers are arranged in series in a multi-stage configuration, arranged in a multi-pass configuration, or a combination thereof,
• wherein the first split pump laser beam and the second split pump laser beam are simultaneously delivered to both the seed laser and the amplifier assembly for automatic temporal synchronization of the seed laser and the amplifier assembly optically, and
• wherein control of the amplified laser energy is implemented by adjusting a time delay of the seed laser while maintaining constant pump energy for each amplifying stage and achieving a stable thermal profile in the amplifying medium.