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      https://www.ias.ac.in/article/fulltext/boms/042/06/0273

    • Keywords

       

      Optical ceramics; Yb:YAG; sintering.

    • Abstract

       

      Laser–host ceramics are a new class of materials and have proved to be a good alternative to the single-crystals. They can be produced in large size with higher concentration of activator ions having more homogeneity which is difficultto achieve with the conventional single-crystal growth technology. Ytterbium (Yb)-doped yttrium aluminium garnet (YAG) is a very attractive laser–host material because of its broad emission band, low quantum defect, no excited state absorption or up-conversion loss and wide range of tunability. In the present work, 10 atm% Yb-doped YAG transparent ceramic was fabricated using nano-powder technology and vacuum sintering. Single-phase nano-powders of Yb:YAG were synthesized by a co-precipitation method and thereafter sintered under vacuum at 1750$^{\circ}$C for 5 h. The as-sintered ceramic samples are ofdark greenish colour which is attributed to the reduction of Yb$^{3+}$ to Yb$^{2+}$ during vacuum sintering. However, after annealing in air at 1350$^{\circ}$C for 8 h they retain their natural colour attributed to the transformations from Yb$^{2+}$ to Yb$^{3+}$. The transmission spectra of the as-sintered polished ceramics show the presence of broad absorption bands near 250, 380, 480 and 630 nm due to the electronic transitions in the Yb$^{2+}$ ion. These bands disappear after annealing in air. The well-established bandsdue to transitions in Yb3+ were observed between 900 and 1000 nm.

    • Author Affiliations

       

      GURVINDERJIT SINGH1 2 S S RESHMA3 RACHNA SELVAMANI1 V S TIWARI1 2 A K KARNAL1 2

      1. Laser and Functional Materials Division, Raja Ramanna Centre for Advanced Technology, Indore 452 013, India
      2. Homi Bhabha National Institute (HBNI), BARC Training School Complex, Anushakti Nagar, Mumbai 400 0943, India
      3. Department of Optoelectronics, University of Kerala, Thiruvananthapuram, India
    • Dates

       
  • Bulletin of Materials Science | News

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