The Lucia laser chain is a Diode Pumped Solid State Laser system based on Yb3+ doped YAG disks used in an active mirror scheme. Front-end and amplifier stages are presented with recent energetic performances (14 J/2 Hz) achieved with improved pumping and extraction architectures. Emphasis is given on the crucial role of ASE and thermal mitigation considerations in engineering the amplifier head.

An experimental study of a static helium gas gap heat switch concept for laser amplification is presented. High single pass gains with large co-sintered ceramic Yb:YAG disks are recorded in the 80-200K temperature range on a diode pumped active mirror amplifier.

The European laser driven fusion project HiPER relies on kilojoule, nanosecond pulse trains with repetition rates close to 10 hertz and high wall-plug efficiency. We propose a scheme based on diode-pumped amplifiers using Yb 3+ :YAG ceramics as gain medium. An active mirror architecture where the high reflection coated side is cooled using a low pressure static Helium gas cell, is proposed.