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High-power Laser Diode End-pumped Nd: The Yvo <sub> 4 </ Sub> Solid-state Lasers Of The Study

Posted on:2004-05-08Degree:MasterType:Thesis
Country:ChinaCandidate:M Y GaoFull Text:PDF
GTID:2208360095450260Subject:Condensed matter physics
Abstract/Summary:PDF Full Text Request
Diode-pumped solid-state lasers are used in many fields, such as military affairs, medical treatment, communications, process and science research, duing to their advantages of high efficiency, good stability, small volume, light weight, long longevity and good quality of laser. Compared with side-pumped solid-state lasers by laser-diode, end-pumped solid-state lasers have very many advantages, such as better mode matched, lower threshold, higher efficiency and so on, so high output power is gained. Nd:YVO4 crystals have a large emission cross section, a wide absorption bandwidth, a high absorption coefficient, a short lifetime in high energy level and a linear polarized laser output, therefore Nd: YVO4 crystals pumped by laser-diode have higher efficiency of pumped, are easy to be coupled with laser-diode, can function in a wider range of temperature, and are adapt to run at a higher repetition rate. A laser-diode end-pumped TEM00 Nd:YVO4 laser was reported operating at 1064 nm with a maximum output power of 18.16 W with respect to the incident pump power of 28.77 W.The summary of paper is as follows:1. Firstly the advantages and pump schemes of DPSSL are introduced, and then hotspots to study, applied area and domestic research development are discussed. Finally the signification and domestic and foreign development of high-power laser-diode end-pumped Nd: YVO4 laser are indicated.2. Output laser properties and thermal effects of high power LD end-pumped solid-state laser are studied thorough. Specially during studying thermal effects of anisotropic laser medium such as Nd:YVO4, some factors in practice are considered:(l) square end faces of the medium; (2) focused Gaussian pumping; (3) the pump spot size being less than the end face size; (4)the temperature of crystal on side face being the same with that of heat sink. The numerical calculation for the heat equation of anisotropic laser medium by laser-diode end-pumped has been studied byusing MATLAB program language. The temperature and its distribution in the medium, such as Nd:YVO4 , were determined. So that, the thermal effect in solid-state laser end-pumped by laser diode can be analyzed quantitatively. Based on the result of the thermal effect study, a high efficient and power TEM0o Nd:YVO4 solid-state laser end-pumped by laser-diode have been designed.3. The experiment on Nd:YVO4 solid-state laser end-pumped by laser-diode is made. Output power of 18.16W is obtained at a pump power of 28.77W on Nd:YVO4 crystal. (l)If optical-to-optical efficiency is defined by output power at 1064nm dividing output power of laser-diode fiber, optical-to-optical is 63.1% at output power of 18.16W at 1064nm. (2)If optical-to-optical efficiency is defined by output power at 1064nm dividing pump power of passing couple system, optical-to-optical is 70.3% at output power of 18.16W at 1064nm. (3)If optical-to-optical efficiency is defined by output power at 1064nm dividing pump power of incident power on Nd:YVO4 crystal(The reflectivity of crystal face of passing light at 808nm has two. The reflectivity of ordinary light is 2.5507 and the reflectivity of extraordinary light is 2.1460. The parameter in process of caculation is 2.1460), optical-to-optical is 75.59% at output power of 18.16W at 1064nm.
Keywords/Search Tags:laser-diode, end-pumped, Nd:YVO4, thermal effect
PDF Full Text Request
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