The WT 307 laser head series are designed for using the laser position transducer system. The laser heads contain a thermally tuned Helium-Neon laser, laser control circuit, and a reference optical receiver. The laser generates a coherent, collimated, two orthogonally linear polarized two-frequency beam of light. The WT 307 laser head series are completely compatible with the HP 5517 laser Head series (manufactured by Agilent Co.) for use with either the HP 5501A laser transducer system or the HP 5527A laser position transducer system.