激光技术
激光技術
격광기술
LASER TECHNOLOGY
2015年
5期
723-726
,共4页
物理光学%涡旋光束%相位分布%拓扑荷
物理光學%渦鏇光束%相位分佈%拓撲荷
물리광학%와선광속%상위분포%탁복하
physical optics%vortex beam%phase distribution%topological charge
为了研究拉盖尔-高斯涡旋光束在传播过程中的相位特性,采用螺旋相位板法获取涡旋光束,从菲涅耳衍射积分出发,对光束在传输过程中的相位变化以及整数阶与分数阶涡旋光束相位奇点的稳定性进行了理论推导和数值模拟。当光束传输一段距离后,光场在观察平面上的等相位线由发散的射线变成了花瓣状的弧线。结果表明,拓扑荷为整数阶的涡旋光束在传输过程中,相位奇点具有稳定性,而分数阶光束的相位奇点不再保持稳定性,其观察平面的光强分布不对称,且涡旋光束中心为暗核的特点消失。该结论对光学微操纵和光信息编码技术的实现具有理论指导意义。
為瞭研究拉蓋爾-高斯渦鏇光束在傳播過程中的相位特性,採用螺鏇相位闆法穫取渦鏇光束,從菲涅耳衍射積分齣髮,對光束在傳輸過程中的相位變化以及整數階與分數階渦鏇光束相位奇點的穩定性進行瞭理論推導和數值模擬。噹光束傳輸一段距離後,光場在觀察平麵上的等相位線由髮散的射線變成瞭花瓣狀的弧線。結果錶明,拓撲荷為整數階的渦鏇光束在傳輸過程中,相位奇點具有穩定性,而分數階光束的相位奇點不再保持穩定性,其觀察平麵的光彊分佈不對稱,且渦鏇光束中心為暗覈的特點消失。該結論對光學微操縱和光信息編碼技術的實現具有理論指導意義。
위료연구랍개이-고사와선광속재전파과정중적상위특성,채용라선상위판법획취와선광속,종비열이연사적분출발,대광속재전수과정중적상위변화이급정수계여분수계와선광속상위기점적은정성진행료이론추도화수치모의。당광속전수일단거리후,광장재관찰평면상적등상위선유발산적사선변성료화판상적호선。결과표명,탁복하위정수계적와선광속재전수과정중,상위기점구유은정성,이분수계광속적상위기점불재보지은정성,기관찰평면적광강분포불대칭,차와선광속중심위암핵적특점소실。해결론대광학미조종화광신식편마기술적실현구유이론지도의의。
In order to study the phase characteristics of Laguerre-Gaussian vortex beam during propagation , the vortex beam was obtained by means of spiral phase plates .Based on Fresnel diffraction integral formula , the phase change of the beam in the propagation process and the stability of vortex beam phase singularities at integer order and fractional order were studied by theoretical derivation and numerical simulation .When the beam was transmitted a certain distance , phase contours of the light field on the observation plane became from diverging rays into petal-shaped arcs .The results show that if topological charge of the vortex beam is integer order , the phase singularity of the beam assumes stability in the propagation process .The phase singularity of fractional order is unstable , intensity distribution on the observation plane is obvious asymmetric and the central darkness gradually disappears .The research results supply theoretical foundation and practical guidance for the application of optical micro manipulation and information coding techniques .