Confocal surface plasmon microscopy with vortex beam illumination for biosensing application

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 the phase pattern on the SLM needs to be frequently updated and the liquid crystal takes time to respond. This slows down the data acquisition 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 publicationAsia Communications and Photonics Conference, ACPC 2015
PublisherOptical Society of America (OSA)
ISBN (Print)9781943580064
Publication statusPublished - 11 Dec 2015
EventAsia Communications and Photonics Conference, ACPC 2015 - Hong Kong Conference and Exhibition Centre, Hong Kong
Duration: 19 Nov 201523 Nov 2015


ConferenceAsia Communications and Photonics Conference, ACPC 2015
Country/TerritoryHong Kong

ASJC Scopus subject areas

  • Computer Networks and Communications
  • Electrical and Electronic Engineering

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