Generation of ultrafast radially polarized pulses through chirp-assisted femtosecond optical parametric amplification

作     者：SaiSai Hu JieFeng Huang XinHao Ren ChangWen Xu ShiXiang Xu DianYuan Fan HaiZhe Zhong SaiSai Hu;JieFeng Huang;XinHao Ren;ChangWen Xu;ShiXiang Xu;Dian Yuan Fan;HaiZhe Zhong

作者机构：International Collaborative Laboratory of 2D Materials for Optoelectronic Science&Technology of Ministry of EducationInstitute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China Shenzhen Key Laboratory of Micro-Nano Photonic Information TechnologyCollege of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China 

出 版 物：《Science China(Physics,Mechanics & Astronomy)》 (中国科学：物理学、力学、天文学（英文版）)

年 卷 期：2022年第65卷第5期

页      面：51-57页

核心收录：

学科分类：0711[理学-系统科学] 070207[理学-光学] 07[理学] 0809[工学-电子科学与技术（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：supported by the National Natural Science Foundation of China(Grant No.92050203) the Natural Science Foundation of Guangdong Province(Grant No.2020A1515010541) the Science and Technology Project of Shenzhen(Grant Nos.JCYJ20200109105606426,JCYJ20190808143419622,and JCYJ20190808145016980)。 

主　　题：radially polarized beam optical parametric amplifier ultrafast lasers spectral broadening optical parametric phase 

摘      要：Radially polarized beams characterized by an axially symmetric polarization distribution can be sharply focused to produce strong longitudinal fields in the vicinity.Future applications of these beams will be facilitated by the availability of higher powers and shorter durations.Currently,the ultrafast radially polarized pulse is typically generated via wavefront reconstruction from conventional linearly polarized states.Achievable pulse duration and intensity limits are strictly dependent on extra-cavity optics.Herein,a chirp-assisted near-degenerate type-II parametric process is presented as a pulse-energy-scalable method of accessing ultrafast radially polarized pulses.In a proof-of-principle experiment,the broadband gain balance between the orthogonally polarized signal components was realized via controlling the chirp of the pump pulse.Through an analogous pulseduration transfer effect,the radially polarized signal inherited the temporal and spectral characteristics of the pump pulse and maintained the radial polarization state of each frequency component of the signal.With a shorter pump pulse,the generation of few-cycle radially polarized pulses should be achievable,which may facilitate a wide range of ultrafast applications such as vacuum electron acceleration and high-harmonic generation.