Analytic Optimization of Near-Field Optical Chirality Enhancement

作者：Kramer Christian; Schaeferling Martin; Weiss Thomas; Giessen Harald; Brixner Tobias^*

来源：ACS Photonics, 2017, 4(2): 396-406.

DOI：10.1021/acsphotonics.6b00887

• optical chirality
• plasmonics
• near-field response
• analytic optimization
• femtosecond polarization pulse shaping
• chiroptical spectroscopy

We present an analytic derivation for the enhancement of local optical chirality in the near field of plasmonic nanostructures by tuning the far-field polarization of external light. We illustrate the results by means of simulations with an a chiral and a chiral nanostructure assembly and demonstrate that local optical chirality is significantly enhanced with respect to circular polarization in free space. The optimal external far-field polarizations are different from both circular and linear. Symmetry properties of the nanostructure can be exploited to determine whether the optimal far-field polarization is circular. Furthermore, the optimal far-field polarization depends on the frequency, which results in complex-shaped laser pulses for broadband optimization.

• 出版日期2017-2