Advancements and Challenges in Sintering Cr4+:YAG Ceramics: A Comprehensive Review on Transparent Ceramic Technology for Q-switched Lasers

Abstract: The resent progress in the technology of transparent ceramics extends the application of CW and pulsed lasers. The parameters of the transparent ceramics are comparable with the single crystals both for active elements (Nd:YAG, Yb:YAG, etc.) and passive Q-switchers such as Cr4+:YAG. Despite the reaching of considerable progress, the sintering of Cr4+:YAG remains a challenge up to now. Up to the present the influence of the CaO, MgO and Cr2O3 additives on the sintering process is poorly understander. Moreover, there is an absence of the unified model of Cr4+ ions formations in YAG ceramics. This factor limits the progress in the development of Cr4+:YAG ceramics. This review focused on the influence of the single additives and their combinations on the sintering trajectory of tetravalent chromium - doped YAG ceramics and the Cr4+ ions formation.