A Master Oscillator Power Amplifier configuration using a Nd:YAG single-crystal fiber to amplify a passively Q-switched microlaser is presented. We achieved the amplification of 80 μJ, sub-nanosecond pulses to the multi-millijoule regime. OCIS codes: (140.3580) Lasers, solid-state; (140.3480) Lasers, diode-pumped; (140.3530) Lasers, neodymium; (140.3380) Laser materials; (060.2290) Fiber materi...