Mephisto MOPA integrates a Mephisto together with up to 4 amplification stages to produce an output of up to 55W at 1064 nm. Other available versions produce 8, 25 and 42W. Each amplification stage is pumped by a fiber-coupled diode array housed inside the head and pumping a separate laser crystal with re-focusing optics to maintain optimum pumping condition and excellent output beam quality. The higher power versions of the MOPA use an optical isolator to prevent damaging back-reflections into the Mephisto NPRO crystal. Because of the high pump and output powers of Mephisto MOPA, liquid cooling of the laser head is required.

Due to the MOPA configuration, the beam properties of Mephisto translate directly into the properties of the high power output beam of Mephisto MOPA (linewidth, stability, frequency tuning, etc.). Mephisto MOPA can be tuned over a 30 GHz range using temperature tuning and PZT tuning of the integrated Mephisto laser. Fast modulation of the laser frequency up to 100 kHz is achieved by modulating the PZT voltage.