For the last decade, neodymium-doped orthovanadate has established itself as the active material of choice for commercial solid-state lasers emitting in the 1 µm range, with output powers from several hundred milliwatts to a few tens of watts, in continuous-wave, short nanosecond Q-switched, or picosecond modelocked pulsed regimes. Its main advantages over other Nd-doped hosts such as YAG are a large stimulated-emission cross section leading to a high gain, a strong pump absorption allowing the efficient mode-matching of tightly-focused pump light, and a natural birefringence resulting in a continuously polarized output. The main drawbacks, however, are rather poor mechanical characteristics and strong thermal lensing, effectively limiting the maximum applicable pump power before excessively strong and aberrated thermal lensing prevents an efficient operation in a diffraction-limited beam, and ultimately the crystal&8217;s fracture. Put aside the power limitation, the association of vanadate with diode end pumping allows for the realization of highly efficient and reliable laser sources based on well-known technologies, which provides an advantage in terms of manufacturability and cost-effectiveness over other high-potential technologies such as disks and fibers. This thesis introduces a novel pumping technique for Nd:YVO4 that allows for the realization of significantly higher-power laser sources with a high optical-to-optical efficiency and diffraction-limited beam quality, while keeping the benefits of a well-established technology. It consists in pumping at a wavelength of 888 nm instead of the classic 808 nm, providing a low and isotropic absorption, which results in a smooth distribution of the absorbed pump light in long crystals, effectively limiting the deleterious effects of high inversion density such as crystal end-facet bulging, high crystal temperature, aberrated thermal lensing, and upconversion. After presenting vanadate&8217;s spectroscopic and physical characteristics, a complete analysis of the heatgenerating effects is performed, allowing for side-by-side simulations of the thermal effects in practical 808 nm and 888 nm pumped systems, and for an evaluation of their respective thermal lensing behaviors. Continuous-wave operation was thoroughly investigated, first in a multi-transversal mode oscillator to assess the maximum optical efficiency with optimum pump-mode matching and the thermal lensing characteristics. A TEM00 resonator was then developed with a single crystal and one pump diode, providing 60 W of output power with an optical efficiency of 55% and a beam quality of M2 = 1.05. This resonator was symmetrically replicated to form a periodic resonator, providing 120 W of output with the same optical efficiency and beam quality. This two-crystal configuration was then modified to an oscillator-amplifier configuration, providing a single-pass extraction efficiency of 53% and a total oscillator-amplifier output of 117 W without any beam-quality degradation. Intracavity doubling of the one and two-crystal configurations
Produktkennzeichnungen
EAN
9783869550282
ISBN
9783869550282
eBay Product ID (ePID)
216221050
Produkt Hauptmerkmale
Produktart
Lehrbuch
Verlag
Cuvillier Verlag
Autor
Louis Mcdonagh
Format
Taschenbuch
Erscheinungsjahr
2011
Maße
Gewicht
246g
Zusätzliche Produkteigenschaften
Ausgabe
1. Auflage
Sprachausgabe
Englisch
Seiten
180 Seiten
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