ピコ秒モード同期Nd : YAGレーザーの試作

Infrared picosecond puIse trains(～7 ns pulse separation) have been obtained from a passive modelocked Nd : YAG laser, Modelocking is achieved by a saturable absorber dye(NDL l12)in 1,2-dichloroethane. The pulse duration is measured by TPF technique to be～30 ps. The efficiency with which energy is transfered from a lamp to the Nd : YAG rod is determined by the delay time of emission from a krypton flashlamp. By varying the impedance characteristics of the krypton flashlamp, the optimum delay time (～105 μs) is obtained. In order to generate the stable picosecond pulse ( ～3 percent fluctuation), the output voltage fluctuation of Power supply must be held within ～2 percent. The SHG (532 nm) and the THG (355 nm) of picosecond pulses from the Nd : YAG laser were also obtained by using KDP(KH₂ P0₄)crystals of Type I and Type II Phase-matching, respectively.