部分相干光被色差透镜聚焦的光谱异常现象

Phenomena of Spectral Anomalies of Partially Coherent Light Focused by a Lens with Chromatic Aberration

研究了色差透镜聚焦宽频带部分相干光,观察到在聚焦光场轴上点出现的光谱奇异现象.结果表明与入射光的光谱比较,聚焦光场某些轴上点的光谱发生很大的变化.这种光谱变化不仅与透镜的色差有关,而且还与入射的部分相干光的相干度有关.当色差一定时,部分相干光空间相干度越大,色差对轴上点光谱的影响就越大.而当部分相干光空间相干度一定时,色差越大,轴上点光谱的变化也就越大.研究结果还表明,在一定的条件下,光谱位移会发生快速变化,即发生了光谱开关现象.

The phenomena of spectral anomalies in the axial points of the focused field, was investigated when partially coherent light is focused by a lens with chromatic aberration. It is shown that the spectrum of the axial points in the focused field is quite different from that of the incident light. This spectral change is not only dependent on the chromatic aberration of the lens, but also on the coherence of the partially coherent light. As the chromatic aberration is fixed, the lager coherence of the partially coherent light is, the more influence of the chromatic aberration on the spectral change of axial focused field. As the chromatic aberration is fixed, the larger the chromatic aberration, the larger change of the spectrum at the axial points of the focused field. The results also indicate that, at some conditions, the rapid change of the spectral shifts, i.e., a spectral switch, takes place in the some points of the focused field.