Cylindrical vector beam fiber laser with a symmetric two-mode fiber coupler  

作　　者：YANG XU SU CHEN ZHIQIANG WANG BING SUN HONGDAN WAN ZUXING ZHANG 

机构地区：[1]Advanced Photonic Technology Lab, College of Electronic and Optical Engineering & College of Microelectronics,Nanjing University of Posts and Telecommunications

出　　处：《Photonics Research》2019年第12期1479-1484,共6页光子学研究（英文版）

基　　金：National Natural Science Foundation of China(91950105);Natural Science Foundation of Jiangsu Province(BK20161521,BK20180742);Nanjing University of Posts and Telecommunications Talents(NY214002,NY215002);Distinguished Professor Project of Jiangsu(RK002STP14001);Six Talent Peaks Project in Jiangsu Province(2015-XCL-023);Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX18_0856)

摘　　要：We demonstrate a passively mode-locked all-fiber laser generating cylindrical vector beams(CVBs)only using a symmetric two-mode fiber optical coupler(TMF-OC)for both high-order mode excitation and splitting.Theoretical analyses show that for a symmetric TMF-OC with appropriate taper diameter,the second-order mode can be excited and coupled into output tap with high purity due to the effective index difference of different modes.Based on the fabricated TMF-OC,the passively mode-locked fiber laser delivers pulsed CVBs at a center wavelength of 1564.4 nm with 3 d B linewidth of 11.2 nm,pulse duration of 2.552 ps,and repetition rate of3.96 MHz.The purity of both radially and azimuthally polarized beams is estimated to be over 91%.Due to simple fabrication method of the TMF-OC and high purity of the generated CVBs,this mode-locked CVB fiber laser with all-fiber configuration has potential applications in optical trapping,optical communications,material processing,etc.We demonstrate a passively mode-locked all-fiber laser generating cylindrical vector beams(CVBs) only using a symmetric two-mode fiber optical coupler(TMF-OC) for both high-order mode excitation and splitting.Theoretical analyses show that for a symmetric TMF-OC with appropriate taper diameter, the second-order mode can be excited and coupled into output tap with high purity due to the effective index difference of different modes. Based on the fabricated TMF-OC, the passively mode-locked fiber laser delivers pulsed CVBs at a center wavelength of 1564.4 nm with 3 d B linewidth of 11.2 nm, pulse duration of 2.552 ps, and repetition rate of3.96 MHz. The purity of both radially and azimuthally polarized beams is estimated to be over 91%. Due to simple fabrication method of the TMF-OC and high purity of the generated CVBs, this mode-locked CVB fiber laser with all-fiber configuration has potential applications in optical trapping, optical communications, material processing, etc.

关 键 词：FIBER MODE PURITY 

分 类 号：TN248[电子电信—物理电子学] TN622