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The Ld End-pumped High Power Nd: The Yvo <sub> 4 </ Sub> Intracavity Frequency Doubling Green Lasers

Posted on:2005-10-14Degree:MasterType:Thesis
Country:ChinaCandidate:L W ZhangFull Text:PDF
GTID:2208360125457777Subject:Condensed matter physics
Abstract/Summary:PDF Full Text Request
Laser-diode (LD) pumped solid-state lasers have become a focus in the field of lasers due to their advantages of high efficiency, compactness, high stability, long lifetime and all solid-state construction. They are widely used many fields, such as military, industry, medical treatment and science research. There has been a great interest in diode pumped solid-state lasers in recent years. Especially continuous wave (CW) laser-diode pumped solid-state lasers of red, green and blue light have showed broad potential applications in color displays. But the difference on the researches of LD end-pump high-power is large between in domestic and in broad. This dissertation has made theoretical and experimental researches around LD pumped high-power CW Nd:YVC>4 /KTP intracavity frequency-doubling green laser. The maximum green laser output power is 4.68W with respect to the incident pump power of 24.56W. The main contents can be summarized as follows:1. In this dissertation, the developments of LD pumped solid-state lasers and the recent researches of Nd:YVO4 intracavity frequency doubling green laser in the world are summarized. Various laser materials used in this type of lasers are classified, and the hot spots in this field research now and in the future are studied.2. Basing on the space-dependent four-level rate equation theory, the output properties of LD end-pumped solid-state lasers are analyzied. The mode-overlap between pumping mode and oscillating mode is studied and numerically simulated on the dimension and position of focusing spot, the angle of pumping laser divergence and the transmission rate of output mirror. Futhermore, the properties of intracavity frequency-doubling are analyzed and numerically simulated. These provide a theoretical basis and guide of our experiment.3. A thermally-insensitive folded cavity is designed on the condition of a high pumping power. With the basis of the thermal lens effects and the wastes due to heat, the influences changing with pump powers are studied. The design principles that equivalent thin lens model and increasing properly the pump radius properly andindecreasing the pump density will minish thermal effects are concluded. Using the thin lens model and the normal transport matrix, the thermally-insensitive cavity is designed, which overcomes thermal effects, hasn't any image-scattering compensators and adapts to high power LD end-pump.4. The experiment of a LD end-pumped high power Nd:YVO4/KTP intracavity frequency-doubled green laser is demonstrated. The phase-matched properties of KTP crystal are studied. With the thermally-insensitive folded cavity and KTP crystal intracavity frequency-doubling, high efficient, high powerful and stable TEMoo green laser can be obtained. Output power of 4.68W is obtained with a 24.56W pumping power. Nd:YVO4 crystal. Optical-to-optical efficiency is 19.06%.
Keywords/Search Tags:Laser diode, end-pumped, thermal effect, Nd:YVO4 crystal, intracavity frequency- doubling, KTP crystal
PDF Full Text Request
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