Study On Coupling Technology Of High Power Laser Diode Array

The pumping source of the high power laser diode-pumped solid state laser thatwas composed of many two dimensional array beams aften used stack structure. It was afact that the above spot was hardly coupled to the laser crystal face.so, In this paper, Thespot was compressed by lens duct and the transmission efficiency and the compressionratio of laser beam were studied.Besides,The tapered fiber was used to further compressspot for requirement.In many cases,High power laser diode array could be applied after the beamshaping.so,In this paper,The coupling technology was studied.In this paper,The elliptical Gaussian model and Zeng LD far-field model wereselected to describe the far-field intensity distribution.Base on these two models,Thelight intensity distribution of bar and stack were calculated by using non-linear principleof coherent superposition ,And far-field intensiy of stack were simulated by computer.By comparison with other coupling sysytem, The lens duct that had greatdevelopment of potentiality was used to reshape high power laser diode array.Using it asthe reshaping system, The expression of the coupling efficiency was derived bymirror-image method.therefore,The relationship of the coupling efficiency and theparameters of lens duct could be obtained by programming.To research coupling efficiency in three aspects.I,The beam was uesd to pump solidstate laser after coupling ,The relationship between the interal expression of couplingeffiency and the parameters of lens duct could be used to optimize the parameters oflens duct.thus,The highly effective pumping efficiency was got.II,The couplingefficiency of the lens duct was studied,The results showed that the influence factors ofcoupling efficiency had the radius of curvature,the length of the lens duct ,the sidelength of the output face and the fast axis divergence angle.The rule of variation of theradius of curvature and coupling efficiency was similar to the length of lens duct amongthem.this could be verified by the basic formula of lens duct.Besides,In order to clearlydescribe the compression of laser beams,The ralationship of compression ratio of theside length and the coupling efficiency was studied,the compression ratio of area aswell.III,Once,The area of laser diode array and the coupling efficiency of lens duct weregiven, The side length of output face,which could be used to select tapered fiber and torealize fiber coupling ,could be obtained by data fitting.Finally,The parameter M was proposed to describe the compression of laserbeam,M was defined as the product of coupling efficiency and compression ratio of area.on the physical concept ,M indicated increasing the ratio of average intensity.The larger M was,the better reshaping effect was.It showed that M could great describebeam shaping system.