Characterization of optical ZnSe ceramics fabricated by spark plasma sintering

Lasers operating in the middle infrared (mid-IR) region are useful for various applications ranging from free-space communication to biological tissue characterization. Transition metal-doped, particularly Cr and Fe, II-VI compounds, are key materials for mid-IR lasers operating in the 2-5μm range. However, producing high-quality transition metal-doped ZnSe crystals is challenging due to limitations in conventional doping methods. This study investigates the fabrication of transparent ZnSe ceramics using spark-plasma sintering (SPS). Sintering was conducted at pressures up to 90MPa and temperatures up to 1100°C under a vacuum with argon gas purging. The resulting ceramics achieved 99.9% density relative to single crystals. Transparent ZnSe and Fe:ZnSe ceramics, with transparencies of up to 52% and 33%, respectively, at 15μm, were fabricated. The successful fabrication of these transparent ZnSe and Fe:ZnSe ceramics demonstrates the viability of SPS as a method for producing TM-doped ceramic mid-IR gain media.