Rare earth doped glass, such as Ytterbium doped Lanthanum Aluminosilicate (Yb-SAL) glass, has demonstrated innovative properties in high power fiber laser applications[1]. Such materials for high power application are often difficult to melt. For glass material, it usually means material preparation in high viscosity region, where bubble elimination and casting will be problematic for melting and quenching technique. The Gas Pressure-assisted Vacuum Viscous Sintering (GPWS) technology has been developed to sinter bubble free glass at middle and high viscosity region (above 104 Pas). The purpose of this work is to characterized the homogeneity of one of the Yb-SAL glass with the composition of 70SiO2-20Al2O3-9La2O3-1Yb2O3 in mole percent. Five aspects of homogeneity Yb-SAL glass prepared by GPWS will be examined: Knots, Striae, Color Centers, Bubbles and Crystals.