Investigation into all-solid-state, pulsed vibronic lasers and their pump sources

Abstract

This thesis is concerned with the design and construction of an all-solid-state, tuneable, pulsed Cr:LiSAF laser and its evolution into an all-solid-state, single-frequency, pulsed Ti:sapphire laser. The initial investigation into the pulsed operation of the vibronic medium CrrLiSAF led to the development of a novel 1.3mum Nd:YLF pump laser. The development of this diode-pumped, Q-switched, 1.3mum Nd:YLF laser is described in detail. This included a comparison of the stimulated emission cross-sections of the 1.321(alphamum and 1.313(0,m lines, which were shown to be equally strong. The frequency-doubling of the 1.321(mum laser in LBO and KTP is compared and the performance of LBO is shown to be superior in this situation. The resulting 660.5nm laser was used as the pump source for a gain-switched Cr.LiSAF laser. The operation of a tuneable, gain-switched CnLiSAF laser with line-narrowing is described in detail. Specifically, the factors limiting its suitability as a diode-pumped, tuneable, single- frequency, pulsed laser medium are addressed. This was achieved, in part, by the construction of an equivalent gain-switched Ti:sapphire laser which was pumped by a frequency-doubled 1mum Nd:YLF laser. The performance of the two gain-switched vibronic lasers is compared when line-narrowed by interferometric means. Ti:sapphire was established as the superior option in this regard and it was developed further, culminating in an all-solid-state, high repetition rate, gain-switched, single-frequency laser. Single-frequency operation was achieved by the technique of injection- seeding the Ti: sapphire resonator with a single-frequency diode laser. The development of this laser, specifically in its high repetition rate form, is considered to be of great interest and potential.