超短脉冲激光频率的线性及非线性扩展

Frequency extending of ultrashort laser pulse with linear and nonlinear processes

通过采用若干激光增益介质和非线性频率变换技术,有效地扩展了皮秒及飞秒激光的波长。在可见光波段,利用自建的高能量400nm倍频皮秒钛宝石激光作泵浦,通过LBO参量放大,得到了波长从450~750nm可调、最高单脉冲能量达30mJ的可调谐皮秒激光脉冲;在红外波段,通过上述方案不仅产生了波长850nm^3.6μm的皮秒闲频光,而且相继利用Cr:Mg2SiO4和Cr:YAG晶体作为增益介质,获得了中心波长分别在1280nm和1450nm波段的飞秒激光脉冲。利用Yb:YAG、Yb:GYSO、Nd:GdVO4、Nd:LuVO4等晶体作增益介质,获得了中心波长1053、1093nm的飞秒激光脉冲及912、916nm的皮秒脉冲。这些具有不同波长特性的超短脉冲激光光源,可望在许多领域获得重要应用。

The available wavelengths of picosecond and femtosecond laser pulses were significantly extended by using of several laser gain media and nonlinear frequency conversion processes. In the visible range, tunable picosecond laser pulses from 460 nm to 750 nm, with the maximum pulse energy up to 30 mJ, were obtained by pumping LBO optical parametric amplification （OPA） system with a home-made frequency doubled picosecond Ti：sapphire amplifier. In the infrared range, we gained not only the idler laser with wavelength from 850 nm to 3.6 μm from the OPA system, but also the femtosecond laser pulses at central wavelengths of 1 280 nm and 1 450 nm by using of Cr：Mg2SiO4 and Cr： YAG as the gain medium respectively. In addition, we successfully obtained femtosecond pulses at wavelengths of 1 053 nm and 1 093 nm and picoseconds pulses at 912 nm and 916 nm by using of Yb：YAG, Yb：GYSO, Nd：GdVO4, Nd：LuVO4 as gain medium respectively. These ultrashort pulse laser souces at different wavelengths will play important roles in many fields.