Fibre optic time-resolved spectroscopy using CMOS-SPAD arrays

K. Ehrlich*, A. Kufcsák, N. Krstajić, R. K. Henderson, R. R. Thomson, M. G. Tanner

*Corresponding author for this work

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

Abstract / Description of output

In vivo fibre optic fluorescence-based sensing is the use of synthesised fluorophores which interrogate the local environment via variation in their fluorescence emission, addressed through an optic fibre. However, the emission intensity is influenced by intrinsic factors such as photobleaching, quantitative factors like concentration dependency and background signals from autofluorescence of tissue and the delivery optical fibre. Many of these problems can be addressed by using time-resolved spectroscopy which measures variations in the fluorescent lifetime. We present a versatile fibre-based time-resolved spectrograph based on a CMOS SPAD line sensor capable of acquiring time and spectral resolved fluorescent lifetime data in a single measurement exploiting the time-correlated single photon counting (TCSPC) technique. It is shown that these TCSPC histograms enable the differentiation between autofluorescence of tissue and synthesized fluorophores, as well as the removal of unwanted fibre background through post-processed time-gating. As a proof-of-principle application the pH- dependent changes in fluorescent lifetime of 5-carboxyuorescein (FAM) are measured.

Original languageEnglish
Title of host publicationOptical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVII
EditorsIsrael Gannot
ISBN (Electronic)9781510605572
Publication statusPublished - 28 Feb 2017
EventOptical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVII - San Francisco, United States
Duration: 28 Jan 201729 Jan 2017


ConferenceOptical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVII
Country/TerritoryUnited States
CitySan Francisco

Keywords / Materials (for Non-textual outputs)

  • CMOS line arrays
  • Laser-induced uorescence
  • Lifetime-based sensing
  • Time-resolved spectroscopy


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