Spark plasma sintering (SPS) is an advanced one-stage, rapid, near-net shape densification technique combining uniaxial pressure with resistive heating. Various transparent ceramics have been successfully fabricated by SPS, despite the existence of inherent carbon contamination and residual pores. Due to the disk-shape of SPS-processed samples, the technique may be suited for producing thin-disk ceramic laser materials. Nevertheless, an in-depth study of these materials has never been reported. With that goal in mind, the major focus of this study was to characterize the laser performance of Nd:YAG ceramics fabricated by one-stage SPS under conventional (60 MPa) and high (300 MPa) applied pressures. In addition to measuring the lasing slope efficiency and threshold, the passive losses associated with each sample were also evaluated. Surprisingly, it was found that in-line transmittance spectra do not provide accurate predictions of laser performance due to the nature of residual porosity. Moreover, homogeneity and beam quality were assessed, and comparisons were drawn between conventional and high-pressure SPS ceramics. This study lays the groundwork for the future of laser materials fabricated by SPS or similar pressure-assisted techniques.

放电等离子烧结 (SPS) 是一种先进的一步式、快速、近净形致密化技术，结合了单轴压力和电阻加热。尽管存在固有的碳污染和残留孔隙，但 SPS 已成功制造出各种透明陶瓷。由于 SPS 处理样品的圆盘形状，该技术可能适用于生产薄盘陶瓷激光材料。然而，从未报道过对这些材料的深入研究。考虑到这一目标，本研究的主要重点是表征在常规 (60 MPa) 和高 (300 MPa) 施加压力下通过一级 SPS 制造的 Nd:YAG 陶瓷的激光性能。除了测量激光斜率效率和阈值外，还评估了与每个样品相关的被动损耗。出奇，结果发现，由于残留孔隙率的性质，在线透射光谱不能准确预测激光性能。此外，还评估了均匀性和光束质量，并对传统和高压 SPS 陶瓷进行了比较。这项研究为未来通过 SPS 或类似的压力辅助技术制造激光材料奠定了基础。