Research on high-precision processing techniques of Nd-phosphate glass laser rods

Abstract

This research presents techniques for fabricating cylindrical laser rods from raw glass using specialized glass cutting, grinding, and polishing machines. A square-cross-section glass rod, cut from a raw glass, is first transformed into an octagonal cross-section by grinding off its four corners. The octagonal rod is then processed into a circular cross-section using a precision cylindrical glass grinder. To polish the end faces of the glass rods, a dedicated holder was designed to securely hold the rods during processing. The fabricated laser rods were then inspected using specialized optical measurement instruments to ensure the highest machining accuracy. The inspection results show that the proposed fabrication method can produce laser rods with a perpendicularity deviation to the cylindrical axis of up to 3 arcminutes, an end-face parallelism deviation of 7.5 arcseconds, and a surface figure error as low as 0.042λ. These parameters are 3–4 times smaller than the standard quality requirements for laser rods, demonstrating that this method can achieve superior quality suitable for high-precision or specialized laser applications.