Rare-Earth Doped Sesquioxide Ceramics for Highly Efficient Mid-Infrared Lasers

Sesquioxide single crystals, such as Y
₂
O
₃
, LU
₂
O
₃
, and SC
₂
O
₃
, have excellent thermal conductivity, thermal expansion coefficient, and relatively small phonon energy. They are the desired host materials for high power solid state lasers [1]. However, due to their high melting temperature it is extremely difficult to grow large size good optical quality sesquioxide single crystals, which prevented the wide applications of the materials as solid-state laser gain hosts. Different from the single crystal growth, ceramics are sintered at a temperature below the melting point, especially with the progress of nano-material synthesis technology high sinterability nano-powders could now be produced. Using nanopowders high quality ceramics can be sintered at even lower temperature. In this talk we show that by using the in-house synthesized nano-powders and the vacuum sintering plus hot isostatic pressing (HIP) method, high optical quality transparent sesquioxide ceramics can be produced even without using sintering aids. Rare-earth doped sesquioxide laser ceramics are fabricated and their high efficiency laser emission at 1.0μm, 2.μm, and 3.0μm wavelength regions are experimentally demonstrated.