SZLASER

This article mainly introduces the pulsed Nd:YAG laser, the output characteristics of the pulsed Nd:YAG laser, and the research on the pulse spectral characteristics.

1. Nd:YAG Laser Crystal The Nd:YAG laser is by far the most commonly used type of commercial solid-state laser. Neodymium-doped yttrium aluminium garnet Y³-x NdxAl 5 O 12 (Nd:YAG)possesses a combination of properties uniquely favourable for laser operation. Undoped pure Y³Al 5 O 12   is a colourless, optically isotropic crystal which possesses a cubic structure characteristic of garnets. Its optical properties are isotropic; the refractive index does not depend on the direction of the light nor its polarization. The cubic structure of YAG favours a narrow fluorescence linewidth, which results in a high gain and a low threshold for laser operation. The YAG host is hard, is of good optical quality and has a high thermal conductivity. The basic physical and chemical properties of YAG crystals are summarized in Table 01. The major laser activator ion for YAG is Nd 3+ , which replaces isomorphic Y 3+   ions. As the Nd 3+  ion radius （0.98A）exceeds that of the Y 3+ ion (0.90A),...