Near-field spectrum retrieving through non-degenerate coupling emission

Yikai Chen,Zhonghua Shen

doi:10.1515/nanoph-2019-0429

Abstract

Abstract 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.

Highlights

The spectrum of near-field probes can characterize their initial radiation properties, which accurately represent the geometric and material properties of the surrounding environment in a subwavelength resolution
We present a scheme to retrieve the initial spectrum of probe molecules in the near field
We consider a probe with a certain spectrum, which in a real experiment should not be known

Summary

Introduction

The spectrum of near-field probes can characterize their initial radiation properties, which accurately represent the geometric and material properties of the surrounding environment in a subwavelength resolution. By recording far-field patterns in all directions, the coupling strength of different radiation angles in two modes can be used to retrieve the probe’s relative ratio between different frequencies.

Results

Conclusion