Increased signals from short-wavelength-excited fluorescent molecules using sub-Ti:Sapphire wavelengths

G Norris, R Amor, J Dempster, W B Amos, G McConnell

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2 Citations (Scopus)


We report the use of an all-solid-state ultrashort pulsed source specifically for two-photon microscopy at wavelengths shorter than those of the conventional Ti:Sapphire laser. Our approach involves sum-frequency mixing of the output from an optical parametric oscillator (λ= 1400-1640 nm) synchronously pumped by a Yb-doped fibre laser (λ= 1064 nm), with the residual pump radiation. This generated an fs-pulsed output tunable in the red spectral region (λ= 620-636 nm, ~150 mW, 405 fs, 80 MHz, M(2) ~ 1.3). We demonstrate the performance of our ultrashort pulsed system using fluorescently labelled and autofluorescent tissue, and compare with conventional Ti:Sapphire excitation. We observe a more than 3-fold increase in fluorescence signal intensity using our visible laser source in comparison with the Ti:Sapphire laser for two-photon excitation at equal illumination peak powers of 1.16 kW or less.

Original languageEnglish
Pages (from-to)200-207
Number of pages8
JournalJournal of Microscopy
Issue number2
Publication statusPublished - Nov 2012


  • animals
  • hosta
  • kidney
  • mice
  • microscopy, fluorescence, multiphoton
  • plant epidermis
  • plant leaves

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