Passive saturable absorber Q-switches for 1 micrometer neodymium:glass and neodymium:YAG lasers

Reported in this thesis is the first time demonstration of Q-switching of a 1 {dollar}mu{dollar}m Nd:Glass and Nd:YAG laser using Cr{dollar}sp{lcub}4+{rcub}{dollar}:FAP, Co{dollar}sp{lcub}2+{rcub}{dollar}:YSGG and BDN Sol Gel as passive saturable absorbers. In addition, the first time Q-switching of 1{dollar}mu{dollar}m Nd:Glass using {dollar}{lcub}rm Cr:sp{lcub}4+{rcub}:GSGG{rcub}{dollar} is also reported. BDN Sol Gel is a material comprised of BDN dye suspended in an organically modified silicate solid gel.; Spectroscopic properties, including absorption coefficients and absorption cross sections at the lasing wavelength were measured for each material to determine their suitability as saturable absorber Q-switches. A Q-switch model was used for both laser systems with each material to predict the Q-switch pulse width, shape and energy and the results were compared to the experiment. Good agreement between theory and experiment were found.; Of all the materials, the BDN Sol Gel produced the best results, with the narrowest Q-switch pulses and one of the highest Q-switching efficiencies. Using BDN Sol Gel, for the Nd:Glass laser, 10.2 nsec pulses were produced with 67% efficiency. For the Nd:YAG laser, 14 nsec pulses with 78% efficiency were produced. The next best performing Q-switch was Cr:GSGG from which the highest Q-switch energy efficiency was obtained from all the Q-switching experiments. For the Nd:Glass laser, 20 nsec pulses with 63% efficiency and for Nd:YAG laser, 24 nsec pulses with 91% efficiency were produced when using Cr:GSGG. Co:YSGG produced 28 nsec Q-switch pulses for the Nd:Glass laser with an efficiency of 11.2% and 36 nsec pulses with a 17.7% efficiency, for the Nd:YAG laser. Cr:FAP produced the poorest Q-switching results, with 48 nsec Q-switch pulses and 9.3% efficiency for the Nd:Glass laser. This was the lowest efficiency obtained from the Q-switching experiments. For the Nd:YAG laser, Cr:FAP produced 65 nsec pulses with a 22.7% efficiency. This was the longest Q-switch pulse obtained from the experiments.