Particle imaging using a transmission wide-field phase confocal microscope

Eugene Astrakharchik-Farrimond, Boris Y. Shekunov, Nicolas B E Sawyer, Stephen P. Morgan, Michael Geoffrey Somekh, Chung W. See

Research output: Journal article publicationJournal articleAcademic researchpeer-review

5 Citations (Scopus)


A phase-sensitive wide field transmission microscope, combining the advantages of both interferometric and confocal techniques, has been developed and applied to analysis of particulates, both in dry powder form and in suspensions. The microscope has also been used in detecting defects in crystals. Confocal operation is achieved by superimposing speckle illumination of a reference beam in a Mach-Zehnder interferometer with a matched speckle pattern of the object beam. It is shown that the phase measurement enables particle size to be determined even when the particle is smaller than the focal spot size. The data acquisition time is below 1ms, making the system suitable for dynamic process measurement. The experimental results are in good agreement with modelled results giving rise to the possibility of simultaneous determination of both the size and refractive index of small particles.
Original languageEnglish
Pages (from-to)104-110
Number of pages7
JournalParticle and Particle Systems Characterization
Issue number2
Publication statusPublished - 1 Apr 2003
Externally publishedYes


  • Confocal microscopy
  • Particle sizing
  • Phase sensitive transmission microscopy
  • Refractive index

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Materials Science (miscellaneous)


Dive into the research topics of 'Particle imaging using a transmission wide-field phase confocal microscope'. Together they form a unique fingerprint.

Cite this