Extending tracking range through structured back focal plane interferometry

Avinash Upadhya*, Yujie Zheng, Li Li, Woei Ming Lee

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


vBack Focal Plane interferometry (BFPI) is a widely used technique in particle tracking, providing high-speed, highresolution measurements. We present Structured Back Focal Plane Interferometry (SBFPI), a modification to BFPI utilizing structured beams and structured detectors [1]. Utilising Conical Wavefront Gaussian Beams and Annular Quadrant Photodetectors, SBFPI significantly increases tracking range while maintaining sensitivity and robustness to aberrations. We studied the variation in detection range and sensitivity over our parameters. A maximum increase in axial and lateral tracking range of 4.25-fold and 1.83-fold was found respectively, concomitant with sensitivity decreases of 53% and 61%. We also found parameter combinations with smaller range improvements but which retain sensitivity, in particular a 2.31 fold axial range increase with a 22.4% reduction in sensitivity, and these can be tuned to each experiment. We also studied the effect of aberrations on signal integrity.

Original languageEnglish
Title of host publicationComplex Light and Optical Forces XV
EditorsEnrique J. Galvez, Halina Rubinsztein-Dunlop, David L. Andrews
Place of PublicationCalifornia, United States
ISBN (Electronic)9781510642379
ISBN (Print)9781510642379
Publication statusPublished - 2021
EventSPIE Conference 11701: Complex Light and Optical Forces XV - Online Only, California, United States
Duration: 1 Jan 2021 → …

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceSPIE Conference 11701: Complex Light and Optical Forces XV
Period1/01/21 → …
Other06-12 March 2021


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