The Research Of All Solid-State Green Lasers For Ophthalmic Therapy

Since the 532nm green light could be heavily absorbed by melanin and hemoglobin while only a small portion is absorbed by lutein, it does little harm to the yellow spot. It is proper to be applied in the angioma treatment around the retina, especially in the surgery in eye. Therefore it has a bright future in the medical field. Up to now, the application of the green light in ophthalmology has been widely studied; furthermore, it has been used in clinical medicine. Laser Diode pumped all solid-state lasers, which has the advantages of high conversion efficiency, excellent beam, compact structure, long lifetime and so on, is of great importance for the miniaturization, high efficiency, and stability of medical treatment equipments. However, Laser Diode pumped green light for ophthalmology has not been comprehensively researched interiorly, and the correlative technology is unmatured, which greatly limits its application. To satisfy the need of fundus oculi disease treatment, we systemically studied all solid-stated green lasers. The primary content reads as follows:(1) The theory of diode end-pumped laser was systemically studied, the special field distribution of the pumping light and oscillating light was analyzed , the threshold pumping power and the relation between the output power and the input power were calculated, the rule of cavity mode design was researched, and the base of designing the laser cavity mode under given pump power and intensity distribution was presented.(2) According to the characteristic of the light source, the coupled system is designed, using a self-focusing len to realize the high efficiency couple between the laser diode and lasing material.(3) According to the requirement of the assignment and the actual needs, a laser system of intra-cavity frequency doubling of Nd:YAG fundamental frequency by KTP crystal is designed. The experimental program of the laser diode end-pumped green laser is claimed, with the experimental equipment presented.(4) After studing the characteristic of the light source used in the program, the optical conduction path is designed, which could conduct the light precisely to the treatment position.The conduction path could be matched with the standard slit lamp saled in the market.