Frequency-doubled light at 532 nm from the microchip Nd:YVO4 lasers is a promising candidate to replace the widely used He-Ne lasers in length metrology due to their superior characteristics, low-cost and rugged structure. In this paper, the spectral characteristics of a commercial microchip Nd:YVO4 laser are investigated. The laser temperature is initially controlled to facilitate the study of longitudinal mode structure of the laser at different pumping current and temperatures. Additionally, a simple method is suggested to obtain a single-mode operation at a relatively wide temperature range, namely from 20 to 25.8 °C, and pumping currents from 300 to 385 mA. The frequency stability is evaluated after controlling the laser temperature to be 1.9 × 10–8 at 1 s. Additionally, parameters that are important for locking the frequency of the laser to a molecular reference transition are investigated such as laser linewidth and the relation between current/temperature and wavelength.

Solid-state lasers are used in length metrology because it has narrow linewidth, single mode and wavelength stability. A simple method uses Nd:YVO4 laser to obtain single mode with stability 1.9 × 10-8 at 1 second.