CAJ | 학술논문

采用复q参量法对脉冲厄米高斯光束在自由空间中的传输进行了分析.在振幅O阶和位相一阶近似条件下,得到其传播过程中载波位相近似公式.运用数值方法和近似公式进行对比研究,发现在脉宽大于5 fs或在远场情况下,两者符合较好.采用近似办法,分别研究了厄米函数阶次、束宽与位置对载波相位的影响.研究表明,在光轴上远场,载波相位趋近于-(m+n+1)π/2,其变化快慢与厄米函数阶次(m+n+1)成正比;束腰宽度越大,则载波相位变化越慢;另外,离光轴距离越远,其导致的载波相位越大,且最大位置都出现在z=Z_R(ω_0)/3处.
채용복q삼량법대맥충액미고사광속재자유공간중적전수진행료분석.재진폭O계화위상일계근사조건하,득도기전파과정중재파위상근사공식.운용수치방법화근사공식진행대비연구,발현재맥관대우5 fs혹재원장정황하,량자부합교호.채용근사판법,분별연구료액미함수계차、속관여위치대재파상위적영향.연구표명,재광축상원장,재파상위추근우-(m+n+1)π/2,기변화쾌만여액미함수계차(m+n+1)성정비;속요관도월대,칙재파상위변화월만;령외,리광축거리월원,기도치적재파상위월대,차최대위치도출현재z=Z_R(ω_0)/3처.
The complex q parameter method is used to analyse the propagation of t the few cycles pulsed Hermite Gaussian beam in the free space within the paraxial condition,and an approxiatie formula for the carrier envelope phase (CEP) is deduced when the zero-order approximation in the amplitude and the firstorder approximation in the phase are used. The validity of the approximation formula is verified by the numerical simulation methods, which shows that they fit well with each other if only the pulse duration is more than 5 femtosecond or the propagation distance is long enough. The order number of Hermite function,the beam waist and the position away from the axis play important roles in the CEP of the few cycles pulsed Hermite Gaussian beam, the conclusion as follows, the CEP trends to -(m+n+1)π/2 in the far field and its variety is inverse proportion with the beam waist on the axis. The distance away the axis is farer,the induced CEP is bigger and the position occurred at the point z=Z_R(ω_0)/3.