Amplified Q-Switched SoliD-State Laser System and Its Interaction with Material.pdf

1、Solid-state laser became these days of great importance where it involved in manyapplications because several major innovations expanded their capability.Among theseapplications is laser-induced plasma spectroscopy LIPS,

2、 sometimes namely optical emissionspectroscopy of laser-induced plasmas, which also have been constantly growing thanks toits intrinsic conceptual simplicity and versatility.The great progress in the solid-state lasertec

3、hnology gives the application laser-induced plasma spectroscopy its importance.Solid-state laser system can operated in different modes.Each mode has its own characteristics,which determine the available different applic

4、ations.Among the wide different modes ofoperation for the solid-state laser system are long-pulse, normal-mode, Q-switched andamplified mode of operation.Amplified mode of operation means laser amplifier.For eachmode of

5、operation there are different mechanisms inside the solid-state laser systemcontrolling the system performance from the electrical energy input to the flashlamp to thelaser pulse output from the oscillator.Different mech

6、anisms inside any solid-state lasersystem could be studied from different point of view.Major innovations are presented withemphasis focused on the laser efficiency.A product of the different efficiency factorsapproach i

7、s developed and applied to describe laser performance.Laser pulse from thedifferent modes of operation for the solid-state laser system, especially; long-pulse (msec),normal-mode (μsec) and Q-switched (nsec) modes of ope

8、ration, has a great interest in theinteraction with materials.Laser-induced plasma spectroscopy LIPS has become a verypopular analytical method in the last decade in view of some of its unique features such asapplicabili

9、ty to any type of sample, practically no sample preparation, remote sensingcapability, and speed of analysis.The technique has a remarkably wide applicability in manyfields, and the number of applications is still growin

10、g.
　　A design for the solid-state laser system from the point of view of the differentefficiency factors inside the laser system was done for long-pulse, normal-mode, Q-switchedand amplified mode of operation.The desi

11、gn is concentrated on the laser systemperformance; it will deal with the laser system performance from the point of view ofengineering.The design criteria will presented arithmetically accompanied by experimentalwork to

12、verify the exactness of the calculated data arithmetically.The pump cavity used inthe experimental work will be designed, and the design considerations will be presented.Thedesigned pump cavity has the geometry of ellips

13、e.Double-elliptical pump cavity will bedesigned for the long-pulse mode of operation and single-elliptical pump cavity will bedesigned for the normal-mode, Q-switched and amplified modes of operation.The stabilitycriteri

14、on for the active optical resonator will be checked through ABCD matrix of the variousoptical components inside the resonator for one round-trip.In addition, the ABCD matrixwill be used to get the pump cavity separation

15、margins from the rear and output mirror.Theoptical resonator loss inside the optical resonator will be calculated experimentally byoperating the solid-state laser system with different output mirror reflectivity, to with

16、standon the practical value for the resonator loss.An analysis for the different parameterscontrolling the solids-state laser system will be done for the long-pulse solid state mode ofoperation, such as; gain coefficient

17、 and single-pass gain, inverted density, fluorescencepower, intracavity power density with the output power and output mirror reflectivity andoutput beam parameter.From the experimental work, the maximum attainable outpu

18、t energyfrom the long-pulse solid-state laser system is 10J with pulse width 20msec for overallsystem efficiency 0.335％ and maximum input energy 4215J, while the maximumattainable output energy from the normal-mode solid

19、-state laser system is 400mJ with pulsewidth 125μsec for overall system efficiency 1.21％ and maximum input energy 25.92].A174mJ output energy with pulse width 9nsec will be obtained from the Q-switched mode ofoperation f

20、or overall system efficiency 1.045％ with input energy 25.92J.For the amplifiedmode of operation, the energy output from the amplifier is 446mJ for laser pulse inputenergy to the amplifier 202.62mJ with gain 2.22 and for

21、electrical input energy to theflashlamp 25.92J with overall system efficiency 2.82％.
　　The laser pulse produced from the three modes of operation; long-pulse (msec),normal-mode (μsec)and Q-switched (nsec)modes of oper

22、ation, will be interacted withepoxide resin target, by focusing the output laser pulse through a focusing lens into targetsurface.There are two different laser pulses for the millisecond laser source according to twodiff

23、erent focusing lenses, while for the microsecond and nanosecond laser pulses, there aretwo repetition rates used for the laser source; 10Hz and 5Hz.Each laser pulse regime (msec,μsec, nsec) has its own power densities, a

24、nd all produce plasma emission from theinteraction with the epoxide resin material.For the first time to the best of our knowledge,Nd∶ YAG laser pulse 1064nm with power density of around 8 × 104 W/cm2 that canproduce pla

25、sma Spectroscopy LIPS emission from a solid target.The electron densityinferred through the Saha-Boltzmann equation for eight line ratios of C Ⅰ and C Ⅱ lines, forthe millisecond and nanosecond laser pulses but cannot de

26、termined for the microsecond laserpulse as there was no sufficient data.The electron temperature was determined using theBoltzmann plot method for the millisecond laser pulse with small spot pulse size andnanosecond lase

27、r pulse with the repletion rates 10Hz and 5Hz, and using line pair methodfor the millisecond laser pulse with large spot size.The maximum plasma temperature andelectron density recorded from the plasma emission (from the

28、 62.87 GW/cm2 nanosecondlaser pulse, 10Hz) were 20410 0K and 5.04×1020cm-3 respectively.On the other hand, theplasma temperature and electron density for the plasma emitted from millisecond laser pulsewith large spot siz

29、e (irradiance around 105 W/cm2) were 10924 0K and 7.39x1017cm-3respectively.Electron density and electron temperature were also studied as functions oflaser power density for the different laser pulses.At the same time,