Near-field spectrum retrieving through non-degenerate coupling emission

• Main Authors: Chen Yikai, Shen Zhonghua
• Format: Article
• Language: English
• Published: De Gruyter 2019-12-01
• Series: Nanophotonics
• Subjects: spectrum; hybrid modes; coupled emission; leakage radiation microscopy
• Online Access: https://doi.org/10.1515/nanoph-2019-0429

We present a scheme to retrieve the initial spectrum of probe molecules in the near field. This is achieved by replacing conventional glass substrates with a hybrid mode photonics chip to create rich and persistent mode distributions and by observing the far-field scattering pattern. The manner of coupling from near field to far field is confirmed by the calculated dependence of the coupled emission signal on the unique material properties. By using an optimization algorithm to retrieve the intensity ratio of near-field optical signals in each frequency band gradually without the need for complicated instruments and time-consuming acquisition processes, our method can achieve broadband non-distortion spectral analysis in an enhanced optical antenna by selecting substrate parameters.