Diagnostic of high-energy Nd-YAG laser polarizer

Abstract

Polarized beam is very vital for operating light switches. High polarization purity is pertinent in high power Q-Switched Nd:YAG laser system. The aim of this project is to diagnose two high-energy polarizers which are commonly used in Q- Switched Nd:YAG laser system namely Glenn-Laser calcite and thin film. The polarization purity was determined by using low power He-Ne laser in place of high power Nd:YAG. The power of He-Ne laser was set at 10 mW with wavelength of 632.8 nm. The beam was aligned to produce parallel plane polarizer. A polaroid polarizer was used as analyzer. The transmission power was measured using a power meter at variable angular rotations from 00 to 360o. The result obtained shows that, both polarizers have produced linear polarization. However, the thin film polarizer had produced a closer result more similar to He- Ne beam polarization. Hence, the thin film polarizer is a better choice to polarize high power Nd:YAG beam since it has higher polarization purity and transmission.