Method for prevention of self-focusing in solid-state lasers

An analysis is made of one of the possible methods of prevention of self-focusing in solid-state lasers emitting short pulses. This method involves radical reduction in the total length of the active medium. Conditions (particularly those relating to the active medium and pump radiation) for achieving a high efficiency are found. It is shown that high values of the specific gain and of the energy stored in the active medium required in such a laser can be achieved using glasses activated with Yb³⁺ and Er³⁺ ions (laser transition producing radiation at the wavelength 1.54 μ) and subjecting them to high-intensity laser pumping.