Confocal surface plasmon microscopy with vortex beam illumination for biosensing application: Label free biosensing application of confocal surface plasmon microscope

Suejit Pechprasarn, Wai Kin Chow, Jingkai Meng, Michael Geoffrey Somekh

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review


We have developed surface plasmon interferometric microscope and demonstrated that by integrating a phase spatial light modulator (SLM) on conjugate back focal plane of confocal microscope objective lens, this enables us to perform surface plasmon phase imaging and phase sensing using phase stepping interferometry over well confined region [1-6]. In this paper, we address one of the key limitations of the system, which IS data acquisition time. Since phase stepping algorithm requires 3 (for 120 degrees step) to 4 (for 90 degrees step) phases in order to obtain a relative phase value between the reference beam and the signal beam; therefore the phase pattern on the SLM needs to be frequently updated and the liquid crystal takes time to response; this slowsdown the data accusation process. Moreover acquiring the phase steps at different times increases microphonic noise and introduces artefacts into real time experiments, such as protein binding. In this paper, we show that a simple and innovative method to overcome these issues is to employ a vortex reference beam provided by 0 to 2π rad topological phase pattern on the SLM; this enables us to obtain multiple phase information in one single shot measurement without updating the SLM pattern.
Original languageEnglish
Title of host publicationBMEiCON 2015 - 8th Biomedical Engineering International Conference
ISBN (Electronic)9781467391580
Publication statusPublished - 4 Feb 2016
Event8th Biomedical Engineering International Conference, BMEiCON 2015 - A-One Hotel Pattaya, Pattaya, Thailand
Duration: 25 Nov 201527 Nov 2015


Conference8th Biomedical Engineering International Conference, BMEiCON 2015


  • Imaging systems
  • Instrumentation and Optical interferometry
  • Microscopy
  • Optical Biosensor
  • Optical modulation

ASJC Scopus subject areas

  • Biomedical Engineering

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