Graded-gain dye laser amplifiers: an experimental investigation

The influence of inhomogeneous distributions of gain and refractive index produced by the pumping radiationon the performance of dye laser amplifiers is discussed. Experimental measurements in capillary cylindrical cells and planar cells are reported for single-pass, double-pass, and ring configurations. Gain factors up to 8.5 x 10(4) have been obtained at low signal input with rhodamine 6G in ethanol. A saturated gain of 5 x 10(3) at 100-mJ output with an over-all efficiency of 0.1% has been achieved without full optimizationof the amplifier parameters. The reported results indicate that a two-stage double-pass amplifier driven by a dye laser oscillator in the milliwatt region can be used as an efficient high energy light source.