Apertureless scanning near-field optical microscopy using heterodyne detection method

Chin Ho Chuang, Yu-Lung Lo

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Heterodyne detection is most common technique in apertureless scattering near-field optical microscopy (A-SNOM), because it can get better signal-to-noise ration (S/N ratio) than the homodyne detection. Fore-researchers provided a rough way to express the heterodyne detection signals in order to avoid the complicated interference signal expressions. Therefore, the explanation is not clear and missing much information in signal processing. In this study, we analyze and verify the amplitude and phase of heterodyne detection signals in complete interference model which including the tip enhancement phenomena and tip reflective background electric field in different harmonics of tip vibration frequency. From our analytical results, we propose meaningful concepts: (1) the high order harmonic tip scattering noise decays faster with high order Bessel function in small phase modulation depth than the near-field interaction signal; (2) longer wavelength and smaller incident angle of incident electric field has better signal contrast, and it opposites traditional optical microscope about shorter wavelength has better resolution.

Original languageEnglish
Title of host publicationSociety for Experimental Mechanics - 11th International Congress and Exhibition on Experimental and Applied Mechanics 2008
Pages1689-1697
Number of pages9
Volume3
Publication statusPublished - 2008
Event11th International Congress and Exhibition on Experimental and Applied Mechanics 2008 - Orlando, FL, United States
Duration: 2008 Jun 22008 Jun 5

Other

Other11th International Congress and Exhibition on Experimental and Applied Mechanics 2008
CountryUnited States
CityOrlando, FL
Period08-06-0208-06-05

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All Science Journal Classification (ASJC) codes

  • Mechanical Engineering
  • Mechanics of Materials

Cite this

Chuang, C. H., & Lo, Y-L. (2008). Apertureless scanning near-field optical microscopy using heterodyne detection method. In Society for Experimental Mechanics - 11th International Congress and Exhibition on Experimental and Applied Mechanics 2008 (Vol. 3, pp. 1689-1697)