Jean-Christophe Chanteloup

14 J/2 Hz Yb3+:YAG diode pumped solid state laser chain.

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.

Active-mirror-laser-amplifier thermal management with tunable helium pressure at cryogenic temperatures.

We illustrate the benefits of a thin, low pressure helium cell for efficient and safe heat removal in cryogenically-cooled active mirror laser amplifiers operating in the [100 J-1 kJ]/[1-10 Hz] range. A homogeneous gain medium temperature distribution averaging 160 K is obtained with a sub-mm helium-filled gap between the gain medium and a copper plate at 77 K. A significant degree of flexibility for tuning the temperature in the amplifier can be achieved by varying the pressure of the helium gas in the 10(2) to 10(5) Pa range.

Current Status on High Average Power and Energy Diode Pumped Solid State Lasers

With ongoing efforts in Europe, the United States, and Asia on power production through inertial fusion, intense work has been focused on proposing and studying Diode Pumped Solid State Lasers (DPSSLs). Such drivers should be able to deliver 1 to 10 kJ at a repetition rate in the 10-Hz range and a wall-plug efficient nearing 10%. Recent achievements will be presented with emphasis on 100 J-class prototypes, which are currently being built.

Deformation of partially pumped active mirrors for high average–power diode–pumped solid–state lasers

We discuss the deformation of a partially pumped active mirror amplifier as a free standing disk, as implemented in several laser systems. We rely on the Lucia laser project to experimentally evaluate the analytical and numerical deformation models.

The LUCIA project: a high average power ytterbium diode pumped solid state laser chain

With the goal to set up a high average power Diode Pumped Solid State Laser (100 Joules/10 Hz/10 ns), the Laboratory for Use of Intense Laser (LULI) is now studying various solutions concerning the amplifier medium, the cooling, the pumping and the extraction architectures. In this paper, we present the last states of these developments and the solutions already chosen.

Large size crystalline vs. co-sintered ceramic Yb 3+ :YAG disk performance in diode pumped amplifiers

A comprehensive experimental benchmarking of Yb(3+):YAG crystalline and co-sintered ceramic disks of similar thickness and doping level is presented in the context of high average power laser amplifier operation. Comparison is performed considering gain, depolarization and wave front deformation quantitative measurements and analysis.

Growth of Large 90 mm Diameter Yb:YAG Single Crystals with Bagdasarov Method

For the first time high optical quality Yb:YAG single crystals with diameter more than 90mm have been grown by Bagdasarov method also known as Horizontal Direct Crystallization.

Improvement of the LULI high-energy CPA laser system focusability and repetition rate using an adaptive optical system

We have implemented on the LULI 100 TW laser facility a closed-loop Adaptive Optics system composed of a large aperature dielectric coated deformable mirror and a home-made shearing interferometer. Significant results have been obtained with this system: not only the beam focusability has been improved to a Strehl ratio of 0.9 but it has also been kept at this level for a sequence full-energy shots, with a repetition rate of 20 minutes, through systematic compensation of the cumulative thermal load generated in the large disk amplifiers.

Impact of Variable Doped Gain Medium on HiPER Multiple kJ / ~10Hz Diode Pumped Beam Lines Design

We discuss advantages of variable doping on gain medium volume requirement, Amplified Spontaneous Emission and thermal management when designing high energy (several kJ) high average power (several tens of kW) Diode Pumped Solid State Laser.

Detection and correction of the spatial phase of ultrashort laser pulses using an optically addressed light valve

The focusing ability of ultraintense laser systems is an important factor difficult to control and for many applications a key parameter is the power density (i.e., the amount of power available in the focal area) rather than the power delivered on the target. In practice, the ability to focus intense beams is limited by phase distortions. We have developed a technique based on a feed-back loop between a spatial phase sensor and a wave-front corrector.1,2