Sialon ceramics is a promising material for decades as a structural material.Due to its excellent mechanical properties, material can be used for further applications.The work is focused on the fabrication of various optical materials for IR windows, remote phosphor for white light emitting diode (WLED) and NIR to visible light up-conversion luminescence materials.α-Sialon phase is important phase to get different optical properties in Sialon ceramic composite because of its ability to accommodate different alkaline earth and rare earth metal ions in its lattice structure.Mg-Sialon was fabricated as a translucent ceramic but single α-Sialon phase cannot be obtained because of small cationic size of Mg2+ that is unable to stabilize α-Sialon phase and thus duplex α-/β-Sialon phase was obtained.Therefore, larger cationic size like Ba2+ and rare earth metal ions were doped to stabilize the α-Sialon phase to get homogenous and granular grains having better translucency.Ba2+, y3+ and Yb3+ doped Sialon ceramics show higher light transmittance and having higher α-Sialon phase.The next step after the fabrication of translucent Sialon ceramics is to apply it in other optical field like WLED and up-conversion material.Different rare earth elements have different electronic configuration and are responsible for conversion of different light source due to their 4f-5d electronic transition.Eu2O3 and Er2O3 were chosen for yellow phosphor and up-conversion material, respectively.