Japanese workers have developed the first neodymium-doped yttrium-aluminium-garnet (Nd:YAG) laser, based on ceramics. Nd:YAG lasers are used for micro fabrication and in medical work. Normally, lasers are made from monocrystalline material. The size and power of these is limited by the size of single crystals that can be grown. However, growing large crystals can take over a month and defects often crop in during growth. Also, while up to 10 per cent of Nd can be incorporated in ceramics, only one per cent is included in monocrystals; researchers have found that 2.4 per cent gives the maximum power output, twice that of the monocrystalline material ( Electronics World , July-August 1996).