Abstract: Device for measuring variations of the gain of a laser amplifier at a particular wavelength, as a function of a pumping energy, said device comprising a source supplying continuous light radiation having the said wavelength and a power Pe, said radiation traversing the amplifier with a given radius, a means for tapping part of the amplified radiation at the output of the amplifier, a photoreceiver receiving said part and measuring the power Ps thereof throughout the pumping time, a means for forming the quotient of Ps by Pe and supplying a signal G(t) representing the variations of the gain as a function of the pumping time, wherein the device also comprises means for supplying a signal E(t) representing the increase in the pumping energy used during pumping and means for extracting a signal G(E) representing the gain variations as a function of the pumping energy for the given radius from the two signals G(t) and E(t), by elimination of the time t.It also relates to a process which utilizes this device.

Abstract: Flash tube comprising a discharge tube made from a transparent material, an electrode located at either end of the discharge tube, one electrode serving to be raised to earth potential and the other to a high potential, an electrical connection connecting each electrode to one of the conductors of a supply line, wherein each electrode is connected to the discharge tube by gaskets and wherein each electrical connection is positioned radially with respect to the discharge tube.The flash tube is intended more particularly for use in the optical pumping of lasers in the visible or near ultraviolet range.

Abstract: Supply device for a flash tube comprising a capacitor, a d.c. voltage source connected to the capacitor, an energy switch located between the capacitor and the flash tube, a circuit able to emit a control pulse for the said switch and a preionization circuit for the flash tube, wherein the preionization circuit comprises a second energy switch connected to the capacitor across a variable resistor, as well as to the flash tube, and a second circuit able to emit a control pulse for the second switch, said second pulse being in advance of the first pulse.Application to the optical pumping of lasers.