Growth of large 90 mm diameter Yb:YAG single crystals with Bagdasarov method

Influence of air annealing temperature and time on the optical properties of Yb:YAG single crystal grown by HDS method

“…Requirements in large size of high quality Yb:YAG crystals are indeed extremely relevant for mentioned applications in the fields of civilian, material processing, communication and military. Yb:YAG single crystal is grown by Czochralski (Cz) [5,6], Temperature Gradient Technique (TGT) [6] and Horizontal Directional Solidification (HDS) [7,8]. Moreover, Cz or TGT method mainly grows in nitrogen or inert (Ar) atmosphere, and inevitably brings in small sizes, central cores and lateral cores.…”

“…Bagdasarov successfully combined the elements of directed crystallization and zone melting, then proposed and developed a method to obtain large size crystals, which was also called Horizontal Directional Solidification (HDS) [9]. The larger Yb:YAG crystals (than Cz and TGT) obtained by this method are reported by Arzakantsyan et al [7], and extracted the available diameter of 92 mm. The critical positive factors of HDS to be mentioned are the larger size, fewer growth defects, homogeneous doping distribution, etc.…”

Defining the optimal gradient doped :YAG disk for room and low temperature diode pumped solid-state laser operations

“…Obtaining an axial gain distribution as homogeneous as possible helps in staying below the parasitic oscillation threshold whatever the depth into the gain medium and reduces the gain medium internal stresses induced by the thermal load [2] .…”

“…The proposed approach requires one first to define a convenient workspace to easily quantify the lasing ion distribution in an HDC engineered gain medium of thickness t (see Figure 1(a)). Since the doping distributions obtained with this growth technique are very linear [1,2] , we shall consider g d [at.%], the doping linear ramp, as the first relevant quantity (horizontal axis). g d /t is the actual gradient, expressed in at.% cm We consider two experimental cases corresponding to the two power amplifiers of the Lucia laser project [3] at the Laboratoire pour l'Utilisation des Laser Intenses (LULI) of the Ecole Polytechnique, Palaiseau, France.…”

Challenges of high power diode-pumped lasers for fusion energy

“…European programmes are supported by Laserlab [47] and are linked to ELI [13] and HiPER [14] . Nevertheless, and although there are engineering solutions to improve the thermal management of the gain medium [48] and the efficiency of the cooling, the maximum output energy record is still the one achieved by Mercury [26] . The current trend for improving efficiency is to be able to combine several advantages while introducing engineering solutions: cryogenic cooling must be addressed to increase the overall efficiency, keeping in mind the efficiency of the cooling cycle.…”