FREQUENCY AND MODE CONTROL OF Q-SWITCHED NEODYMIUM: YAG LASERS

This dissertation presents two experimental studies which extend the usefulness of Q-switched Nd:YAG lasers in nonlinear optical and spectroscopic applications.; The major part of this dissertation describes injection locking of Q-switched Nd:YAG lasers. A transient injection locking theory is developed which describes single axial mode selection in Q-switched or gain switched laser oscillators. Comparison is made with experiments carried out for an unstable resonator Q-switched Nd:YAG oscillator. We demonstrate that injection locking provides very stable single axial mode output with Fourier transform limited bandwidth from a high power Q-switched Nd:YAG oscillator.; The second part of this dissertation describes high phasematching temperature Lithium Niobate single crystals for efficient second harmonic generation of 1.064 (mu)m Nd:YAG lasers. Growth procedures of high phasematching temperature Lithium Niobate crystals are investigated for various concentration of excessive Lithium Oxide and co-doped Magnesium Oxide in melt composition and for various growth parameters. We have grown high quality Lithium Niobate crystals with a phasematching temperature which is above the optical index damage annealing point. We have evaluated the improved Lithium Niobate crystal advantages of large nonlinearity and ability to achieve non-critical phasematching condition by efficiently doubling a TEM(,00) and multi-transverse mode cw lamp pumped acoustic-optic Q-switched Nd:YAG laser.