Diode-pumped 1.54 /spl mu/m Er-Yb:GdCOB lasers

We present the investigation of longitudinally pumped microchip Yb-Er lasers based on new crystalline medium GdCa/sub 4/O(BO/sub 3/)/sub 3/. The main potential advantage of these crystals over Er-Yb glasses is the higher thermal conductivity, which may lead to higher thermal damage threshold. The advantage of GdCa/sub 4/O(BO/sub 3/)/sub 3/ (GdCOB) over YCOB is its lower melting point are discussed.