摘要
由于相位匹配条件和非线性晶体透光范围的限制,400nm蓝光抽运的飞秒β-BaB2O4(BBO)光参量放大(OPA)输出的参量光调谐范围有限,很难得到波长小于460nm的蓝光和近紫外光.实验采用1kHz钛宝石九通啁啾脉冲放大器的倍频蓝光作抽运光,超连续白光作种子光,在Ⅰ类非共线相位匹配条件下,利用宽带的飞秒BBOOPA,在一定的实验参数下获得了530—810nm放大的信号光,以及810nm—1·7μm波段范围的闲频光.与此同时,还获得了410—700nm连续可调的闲频光的二次谐波,其与闲频光层叠分布,单脉冲能量为2·6μJ,转换效率大于5%.仅利用单块晶体的飞秒BBOOPA就可以获得410—810nm连续可调的飞秒脉冲输出,从而为更多研究和应用的需要提供了重要的光源.对飞秒光参量放大中闲频光二次谐波产生的条件也进行了理论分析.
For femtosecond optical parametric amplification (OPA) pumped with a 400 nm blue laser, limited by phase-matched condition and nonlinear crystal transparent range, the tuning range of the output parametric laser is restricted, and the blue and the near UV lasers with wavelength less than 460 nm are difficult to obtain. In our experiment, we adopted the second harmonic of a Ti: sapphire nine-pass chirp pulse amplifier at 1 kHz repetition rate as the pump beam, and the white-light supercontinuum as the seed beam; thus, by a type-I noncollinear phase-matched broad bandwidth beta-BaB2O4 (BBO) OPA, with certain experimental parameters, the amplified signal beam from 530 nm to 810 nm and the idler beam from 810 nm to 1.7 mu m were obtained; at the same time, the idler second harmonic from 410 nm to 700 nm was obtained also. The idler second harmonic was cascaded with the idler beam, its pulse energy was 2.6 mu J and the conversion efficiency was greater than 5%. Therefore, femtosecond pulses tuned continuously from 410 mn to 810 nm can be obtained by the 13130 OPA with a single crystal only, thereby a useful source is provided for more investigations and applications. In this paper, we also have theoretically analyzed the generation condition of the idler second harmonic for femtosecond OPA.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第8期3675-3679,共5页
Acta Physica Sinica
基金
国家重点基础研究发展规划(批准号:G1999075201)
高等学校博士学科点专项科研基金(批准号:20030056021)
高等学校优秀青年教师教学科研奖励计划资助的课题.~~
