In order to mitigate the dopant concentration gradient by post-growth diffusion method, high optical quality Cr<sup>2+</sup>:ZnSe ceramics had been prepared by hot-pressing method with powders being diffusion doped in a previous step, which reduced the concentration gradient down to a grain size level. A optimal combination of sintering parameters, including
temperature, pressure, dwell time, have been determined (1050°C/150MPa/2h) according to background absorption
intensity. Comparison with diffusion doped CVD-grown ZnSe showed a stronger background absorption and blueshifted
emission peak, both indicating scattering sources inside material. Micro-structure observation proved the
inference above as being residual pores and inclusions, which could be eliminated or reduced by, as suggested here,
preliminary treatment of powders and enhancement of densification pressure and dwell time.