Abstract
ABSTRACT High power green laser has a lot of application. We have got 34.2-watt average power of laser at 532nm from a intracavity frequency doubled YAG laser. KTP crystal was used as the frequency doubler. The advantage of Quasi-CW pumping for frequency doubling was taken, the output power of harmonic wave with Quasi-CW pumping is higher than CW pumping. The influence of the polarization property of YAG laser on frequency doubling efficiency was theoretically analysed, and the optimum orientational angle for frequency doubling crystal was found inaddition to the traditional phase matching condition. Some experimental work, the parameters and properties of the laseir was reported. 1. INTRODUCTION High power green laser has a lot of application, such as pumping dye laser, ocean development, laser medical treatment laser high speed photography or holography, isotope separation and laser lighting or communication under sea.Since the high efficent frequency doubling crystal KTiOP04 (KTP) was manufactured in 1976[lJ, frequency doubled YAG laser has developed rapidly and shows tendency to replace the normal green laser sources, such as Kr+ laser and Cu vapor laser, with its advantages of long life, low price and small size. In 1982 the output power of frequency doubled YAG laser with KTP crystal was 5.6 wattst2!. In 1983, it devoped to 10 watts^J, and in 1984, it reached 20 watts in XMR cooperation^4]. We developed study in frequency doubling both in theory and experiment since 1983, and got 8*7 watts^5! average output power of green laser in 1985 in a Q-switched intracavity frequency doubled YAG laser using KTP crystal grown by China. In August, 1986, 34.2-watt green laser was achieved in our laboratory, which satisfied the leading level in the world^6-]. A commercial type of this kind of laser has made to sell with 20-watt average output. In this paper some creative work both in theory and experiment is reported.2. THEORETICAL WORK2.1 Quasi-CW pumpingYAG laser is pumped by Kr CW lamps or Xe pulse lamps in general to get high average output power and high peak power respectively. We choose Quasi-CW pumping (see Figure 1) according to the relation of frequency doubling efficiency (FDE) and intensity of fundamental wave.(see Figure 2)Z) = 1.0247-th2 [3.07xlO-4 'E0'Z] [7] (1)where Eo is the total fundamental wave field£3 is the frequenvy doubling wave fieldZ is the length of KTP crystal0Figure 1.Electric current of Kr lamps in Quasi-CW pumpingFigure 2. FDE as a function of the total power of fundamental wave at different leng th of frequency doubling crystal
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call