飞秒脉冲的远场反射谱特性

Properties of reflected spectrum of femtosecond light pulse in far zone.

从平面波的角谱表示出发,得到了超短脉冲光束由分层介质表面反射的频谱特性,数值计算给出了飞秒高斯脉冲经自由空间中介质薄膜反射的远场谱分布.由于光与介质的相互作用,反射谱呈现谱线变窄、红移、蓝移以及出现旁瓣而分裂成多重谱线的现象.

The spectral properties of ultrashort pulse beam reflected from a stratified medium are studied by the representation of an angular spectrum of plane waves. As an example, the far-zone spectra of the femtosecond light pulses with Gaussian shape reflected from a dielectric film in free space are analyzed in detail. Results of numerical calculation show that the spectra may change in many different ways, compared with the incident field, exhibiting red shift, blue shift, line narrowing and splitting into multiple lines because of the interaction between light field and medium.