ULTIMATE BEAM EXPANSION RATIOS FOR ND: YAG LASER HARMONICS

Beam expander plays a key role in laser devices for remote detection for transmission unit. The study is conducted for Nd: YAG laser wavelength 1064 nm and its harmonics, namely the second harmonic generation wavelength 532 nm, the third harmonic generation 355 nm, and the fourth harmonic generation 266 nm. Determination of expansion ratios of beam expander for specific wavelength and detection range is the key in beam expander optical design for determining minimum possible laser spot size at the target. Knowing ultimate expansion ratio implies to reduce laser transmitting unit dimensions and increase performance efficiency of receiving unit