Design of a selectively reflecting pump source for a laser

It is shown that the deposition of selectively reflecting coatings on a pump lamp results in an effective absorption of the reflected radiation in the discharge plasma followed by reemission at wavelengths which include the transmission bands of the selective-reflection filter. This increases the pumping efficiency. It is shown that in the case of a xenon discharge pump source with a reflection coefficient ~0.9 outside the absorption bands of a neodymium-doped yttrium aluminum garnet crystal the optimal efficiency of a pump source increases by a factor of 2–3; the corresponding improvement in the case of ruby is 1.5–2. The best results are obtained for pulsed discharges of fairly high optical density when the use of selective fillings is not very efficient.