Ar气中超连续谱产生的研究

采用中心波长为800nm，脉宽30fs的超快激光在Ar气池中产生了200—1000nm宽范围的超连续谱.通过改变激光脉冲的初始啁啾量、单脉冲能量、气体压强以及聚焦长度等条件，详细研究了获得稳定的超宽频谱的条件.结果表明，单脉冲能量为20mJ，附带29×10⁴fs²正色散的啁啾脉冲用f=50mm的凹面镜在15m长，23×10⁵Pa的Ar气中聚焦，得到稳定的频谱宽度达10³THz的超连续谱.还测量了光斑关键词：非线性效应超连续谱初始啁啾光斑远场模式

Ultrabroadband continuum spectrum generated in Ar gas

We observed the supercontinuum in Ar during the propagation of a femtosecond pulse with wavelength of 800nm，repetition rate of 10Hz and pulse duration of 30fs. We studied the supercontinuum when changing the chirp of the pulse，pulse energy，pressure in the cell and the focal length to find the optimal conditions. And we observed the steady broadest supercontinuum extending up to 200nm with the pulse of 20mJ energe，29×10⁴fs² chirps when the focal length was 500mm and the pressure of the cell was 23×10⁵Pa. We measured the far-field pattern of the continuum and found the divergence angle of the white light to be 31mrad.