888 nm pumping of Nd:YVO4 for high-power high-efficiency TEM00 lasers
888 nm pumping of Nd:YVO4 for high-power high-efficiency TEM00 lasers
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DOI:
10.1117/12.700200
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发表时间:
2007-02
期刊:
影响因子:
--
通讯作者:
L. McDonagh;R. Knappe;A. Nebel;R. Wallenstein
中科院分区:
文献类型:
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作者:
L. McDonagh;R. Knappe;A. Nebel;R. Wallenstein
Nd:YVO4 is a widely used gain medium in commercial lasers providing up to several tens of watts in a diffraction limited beam. Its high gain favors high repetition rates and short pulses in nanosecond Q-switched and picosecond mode-locked regimes. However, output power is limited by strong thermo-optical effects leading to an aberrated thermal lens and ultimately the crystal's fracture. In this contribution, we present the optimized pumping of vanadate at 888 nm, benefiting from polarization-independent absorption, reduced quantum defect and very low absorption coefficients compared to the common pump wavelengths of 808 and 880 nm. After a presentation of the principle and the key characteristics of a high-power fiber-coupled end-pumped multimode oscillator, a series of systems based on this pumping technique are presented. A compact 60W high-efficiency TEM00 CW oscillator first proves the potential for high-power high-beam-quality systems. A CW intracavity-doubled system provided 62 W of power at 532 nm. A cavity-dumped Q-switched oscillator providing up to 47 W of average power with 6 ns long pulses at all repetition rates was investigated. Passive mode-locking of an oscillator providing 56 W of output power was achieved with a saturable absorber mirror. Finally, a high-power oscillator was amplified with high efficiency in a power amplifier based on the same pump/crystal configuration. The wide range of systems demonstrated illustrates the simplicity and flexibility of 888 nm pumping for extending the benefits of vanadate in the higher power range.