Energy parameters of a large-aperture prism active mirror

The main energy parameters of an active-mirror amplifier were determined using rectangular prisms made of LGS-59 neodymium glass as the active elements. The efficiency of conversion of the pump energy into the energy stored in the active medium was ~ 3% when the inhomogeneity of the distribution of the gain over the aperture was less than 12%. The linearity of variation of the small-signal gain within a wide range of pump energies demonstrated a low level of the superradiant noise, which in this geometry of the active elements was considerably less than the spontaneous noise.