Based On Photodynamic Therapy Apparatus Of All Solid State Green Laser Light Source

In recent years, with the development of modern laser medicine, the for-eign advanced laser medical equipments can treat a variety of cutaneous he-mangioma, and curative effect is distinct, side effect is small, but the in-strument expensive, treatment is too high, and it is difficult to carry out in municipal the following the hospital. Now generally people used light-pump solid state lasers, dye laser and copper steam lasers for the field, and th-ere is never mature products based on the intelligent all solid green laser Photodynamic Therapy (PDT) instruments, mostly stay in laboratory stage, es-pecially to meet medical applications product still is not mature enough, s-till can’t realized industrialization. In view of the Beijing301and a number of dermatological department of hospital of in depth research and c-linical treatment needs, it is carried out to the research topic of intelli-gent all solid-state green laser PDL instrument.This paper studies the lig-ht source and beam shaping about PDT instrument, main content as follows:1This paper first introduces the progress and principle of the PDT and laser therapy of the cavernous hemangioma, summarizes the existing laser tr-eatment equipment in the treatment of the merits and demerits of the heman-gioma.2This paper briefly reviews the nonlinear frequency conversion techno-logy, and deduces the three waves interaction of the coupled wave equation and uniaxial crystal of refractive index ellipsoid. Based on uniaxial crys-tal double frequency of theory, in consideration of the walk-off-effect, for example the BBO, gives the negative uniaxial crystal effective nonlinear coefficient calculation.3All solid-state side-pump Nd:YAG cylindrical rod of the thermal effect is calculated and analyzed by the LASCAD software, and according to the ABCD beam transformation matrix theory, all solid-state side-pump Z cavity type structure is calculated, in considering gain medium and nonlinear crystal thermal effect, cavity length parameters is optimized by the Matlab. On the basis of the theory study, experiment won the repeat frequency9KHz,17.27W green laser output.4Green laser beam shaping experiment to PDT instrument, many kinds of beam shaping methods are compared, such as aperture aperture, birefringence lens group, the diffractive optical elements, micro lens arrays, liquid cry-stal spatial light modulator and the spherical lens etc. The paper focuses on the spherical lens group of beam shaping principle, and beam expander and handle system design process and principles. Beam shaping experiments are proceeded respectively to use the solid side-pump line cavity, end-pump V cavity and side-pump Z cavity output green laser as the light source, shapi-ng aim is to put a gaussian beam into flat-top beam. Through the test, output outline of beam are given respectively, and the test results are analyzed. Among them of the green laser source end-pump V cavity realized the ideal beam shaping experimental result, but can not meet the power source product. The last, all solid-state side-pump Z cavity is calculated by the LASCAD, and the experimental result is not ideal, to be further optimized design of cavity parameters.