Dispersion-based pulse shaping for multiplexed two-photon fluorescence microscopy.
ABSTRACT We demonstrate selective two-photon excited fluorescence microscopy with shaped pulses produced with a simple yet efficient scheme based on dispersive optical components. The pulse train from a broadband oscillator is split into two subtrains that are sent through different amounts of glass. Beam recombination results in pulse-shape switching at a rate of 150MHz. Time-resolved photon counting detection then provides two simultaneous images resulting from selective two-photon excitation, as demonstrated in a live embryo. Although less versatile than programmable pulse-shaping devices, this novel arrangement significantly improves the performance of selective microscopy using broadband shaped pulses while simplifying the experimental setup.
- SourceAvailable from: Paola Borri[show abstract] [hide abstract]
ABSTRACT: We demonstrate coherent anti-Stokes Raman scattering (CARS) microspectroscopy using a single Ti:sapphire laser oscillator and simple passive optical elements. Spectral selection by dichroic mirrors and linear chirping by glass elements creates a vibrational excitation tuneable over a large spectral range (∼800–2200 cm <sup>-1</sup>) with adjustable spectral resolution (∼10–100 cm <sup>-1</sup>) . We furthermore demonstrate the applicability of differential CARS, enhancing the chemical selectivity, with the proposed single-laser configuration.Applied Physics Letters 09/2009; · 3.79 Impact Factor
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ABSTRACT: We demonstrate frequency differential CARS (D-CARS) using femtosecond laser pulses linearly chirped by glass elements of high group-velocity dispersion. By replicating the Pump-Stokes pair into a pulse train at twice the laser repetition rate, and controlling the instantaneous frequency difference by glass dispersion, we adjust the Raman frequency probed by each pair in an intrinsically stable way. The resulting CARS intensities are detected simultaneously by a single photomultiplier as sum and difference using lock-in detection. We demonstrate imaging of living cells with strongly suppressed non-resonant background. We also show D-CARS using a single femtosecond laser source.Proc SPIE 01/2011; 7903.