Henesian M A, Swift C D, Murray J R
Opt Lett. 1985 Nov 1;10(11):565-7. doi: 10.1364/ol.10.000565.
We studied the growth from amplified spontaneous emission of stimulated Raman scattering in air using a 20-cm-diameter, linearly polarized, 1053-nm laser beam propagating over a 20-150-in air path. For 2.5-nsec square pulses we found about 1% conversion on the S(8) and S(10) rotational Raman lines of nitrogen at an intensity-length product of 12 TW/cm, which implies a small-signal gain coefficient of 2.5 cm/TW. For 1-nsec square pulses, 1% conversion requires an intensity-length product of about 16 TW/cm. The beam quality deteriorates severely above Raman threshold.
我们使用一束直径20厘米、线偏振、波长1053纳米的激光束，在20至150英寸的空气路径中传播，研究了空气中受激拉曼散射的放大自发辐射的增长情况。对于2.5纳秒的方脉冲，我们发现在强度-长度乘积为12太瓦/厘米时，氮气的S(8)和S(10)转动拉曼线上有大约1%的转换率，这意味着小信号增益系数为2.5厘米/太瓦。对于1纳秒的方脉冲，1%的转换率需要强度-长度乘积约为16太瓦/厘米。在拉曼阈值以上，光束质量会严重恶化。
