CAJ | 학술논문

构建了一种能够直接输出高功率贝塞尔超短脉冲的光纤激光放大器.该方案基于在光纤端面特殊设计和制备的微型负轴锥镜,针对常规超短脉冲光纤激光放大系统所设计,不需要引入其他分立整形器件,避免了目前基于轴锥透镜产生贝塞尔光束的通用方法所带来的额外烦琐准直工作,极大简化了产生贝塞尔光束的方法.其中的微型负轴锥镜由聚焦粒子束刻蚀法在一段掺镱大模场光子晶体光纤的端面制备,它和光纤激光系统中的固有准直透镜构成了集成化的光束整形器件.基于数值模拟结果成功搭建的系统与理论设计一致,直接输出了在米量级具有高度准直无衍射特性的啁啾皮秒贝塞尔超短脉冲波包,平均功率高达10.1 W,对应脉冲能量178 nJ,经过光栅对压缩后脉冲宽度可达140 fs.
구건료일충능구직접수출고공솔패새이초단맥충적광섬격광방대기.해방안기우재광섬단면특수설계화제비적미형부축추경,침대상규초단맥충광섬격광방대계통소설계,불수요인입기타분립정형기건,피면료목전기우축추투경산생패새이광속적통용방법소대래적액외번쇄준직공작,겁대간화료산생패새이광속적방법.기중적미형부축추경유취초입자속각식법재일단참의대모장광자정체광섬적단면제비,타화광섬격광계통중적고유준직투경구성료집성화적광속정형기건.기우수치모의결과성공탑건적계통여이론설계일치,직접수출료재미량급구유고도준직무연사특성적조추피초패새이초단맥충파포,평균공솔고체10.1 W,대응맥충능량178 nJ,경과광책대압축후맥충관도가체140 fs.
@@@@High power Bessel pulses directly output from a fiber-based amplifier system are demonstrated. A compact solution based on the inverse micro-axicon (IMAX) on fiber end is proposed for the conventional ultrashort pulse fiber laser system to enable the direct generation of high power Bessel pulses from lasers without any additional exhausting alignments. The IMAX is fabricated on one facet of a ytterbium-doped large mode area fiber by focusing ion beam technique and constitutes an integrated beam shaper in combination with an inherent collimating lens in the fiber laser system. The experimental results accord qualitatively with the simulations. The system can directly generate chirped Bessel pulses with diffraction-free propagation in meter-scaled free space. The highest average power of such a wavepacket can reach 10.1 W, correspongding to 178 nJ, and the pulse duration can be dechirped to 140 fs.