Jovanovic Igor, Brown Curtis G, Ebbers Christopher A, Barty C P J, Forget Nicolas, Le Blanc Catherine
Lawrence Livermore National Laboratory, Mail Code L-470, 7000 East Avenue, Livermore, California 94550, USA.
Opt Lett. 2005 May 1;30(9):1036-8. doi: 10.1364/ol.30.001036.
A new high-contrast, high-gain optical parametric chirped-pulse amplifier (OPCPA) architecture is demonstrated in periodically poled KTiOPO4 (PPKTP). This architecture overcomes parametric fluorescence contrast limitations of the OPCPA in periodically poled materials. The scheme is based on two passes of a single relay-imaged pump pulse and a free-propagating signal pulse through a 1.5 mm x 5 mm x 7.5 mm PPKTP crystal. The output energy of 1.2 mJ is generated at a center wavelength of 1053 nm by 24 mJ of pump energy. A prepulse contrast level of > 3 x 10(7) was measured with > 10(6) saturated gain in the amplifier. Amplified pulses were compressed to 200 fs. This simple and versatile concept requires only a modest pump energy from a commercial pump laser and represents a possible high-contrast front end for high-energy Nd:glass-based petawatt-class lasers.
一种新型的高对比度、高增益光学参量啁啾脉冲放大器（OPCPA）架构在周期性极化铌酸钾钛（PPKTP）中得到了验证。这种架构克服了周期性极化材料中OPCPA的参量荧光对比度限制。该方案基于单个中继成像泵浦脉冲和自由传播信号脉冲通过一块1.5毫米×5毫米×7.5毫米的PPKTP晶体的两次通过。通过24毫焦的泵浦能量在中心波长1053纳米处产生了1.2毫焦的输出能量。在放大器中测量到预脉冲对比度水平>3×10⁷，增益饱和>10⁶。放大后的脉冲被压缩到200飞秒。这个简单且通用的概念仅需要来自商用泵浦激光器的适度泵浦能量，并且代表了一种可能用于高能钕玻璃基拍瓦级激光器的高对比度前端。
