OPTICALLY DENSE ACTIVE MEDIA FOR SOLID-STATE LASERS

The author has examined the potential of optically dense active media in solid-state lasers using, as an example, YSGG:Cr**3** plus ,Nd**3** plus active elements with a chromium concentration equals 1 multiplied by 10**2**0 cm**-**3, and a neodymium concentration equals 3 multiplied by 10**2**0 cm**-**3. One element had a square cross section (dimensions were 0. 5 multiplied by 0. 5 multiplied by 8 cm**3) and the other was cylindrical (0. 4-cm-diameter, 7-cm-long). The optical density and geometrical size were chosen so that the limiting pump regime would be encountered at a relatively low average power. The solid-state laser pump cavity was cylindrical. This made it possible to compare the square (zig-zag) and cylindrical active elements under identical conditions. The results are presented. An effect, called the static STON-effect (smoothing of thermo-optical inhomogeneities), is discussed.