Study On High-Power Diode End-Pumped All-Solide-State Laser

From its appearance, lasers have been widely used in industries, medicines, and scientific researches, etc.. Especially, laser diode （LD） end-pumped solid-state lasers （LDPSSLs）, with the advantages of high efficiency, excellent beam quality, compact structure, superior output stability and long life-time, are widely recognized as the potential candidate for the next-generation laser sources. In this dissertation, infrared, green and ultraviolet LDPSSLs have been investigated theoretically and experimentally, with the incooperation of LD fiber-coupling technology and four-level rate equations. The laser operation is optimized and industrialized 1064nm, 532nm and 266nm LDPSSLs have been achieved. These lasers are widely utilized in the industries, like material processing and manufacturing. In detail, the main contents of the dissertation can be described as following,1. The history and application of diode lasers are introduced. With the appearance and development of LDPSSLs, the evolvement and current advances of all-solid-state laser technology are presented.2. From the laser resonating theory and Q switching analysis, the operation characteristics and lasing threshold of LDPSSL are discussed, Two LDPSSL schemes are designed and adopted in building high power fiber coupled LD modules, with the output power reaching 32W and efficiency higher than 80%. These parameters present the leading levels in the world.3. With the self-prepared fiber coupled LD modules, the industrial laser resonator is optimized. Two lasers, one single LD end-pumped acousto-optical Q-switched infrared lasers and one double LD pumped Nd:YVO₄ acousto-optical lasers, are realized. The output powers of these lasers approaches 10W and 20W and accordingly, three series of products are formed.4. With the proper thermal and cooling analysis, the 10W all-wind-cooling LDPSSL is optimized. The laser can be stably operated with 0.1W degradation after 1500 hours of testing operation. This laser has its specification meeting the requirement of real industrial utilization and is currently under mass production. It is demonstrated that MTBF （Mean Time Between Failures） of this model reaches 5000 hours, which represents the advanced level of the world.5. With cavity-dumping technique and a pulsed LD as the pump source, an end-pumped one hundred Hertz electro-optical cavity-dumped Nd:YAG LDPSSL is constructed with 5mJ of 1064nm pulse output. With an additional single-passage laser amplification stage and 30mJ pulsed LD energy input, 10mJ of 1064nm laser pulse is obtained with a pulse-width of 4ns. The M² beam quality factor is better than 1.2. With the extracavity doubling and tripling frequency conversion schemes, 5mJ of 532nm and 2mJ of 266nm are obtained with the ultraviolet laser performance reaches that of the leading domestic level. Prototype lasers are produced and utilized.