Wide-field coherent anti-Stokes Raman scattering microscopy with non-phase-matching illumination

Abstract

We have developed and tested a wide-field coherent anti-Stokes Raman scattering (CARS) microscopy technique, which provides the simultaneous imaging of an extended illuminated area without scanning. This method is based on the non-phase-matching illumination of a sample and imaging of a CARS signal with a CCD camera using conventional microscope optics. We have identified a set of conditions on the illumination and imaging optics, as well as on sample preparation. Imaging of test objects proved high spatial resolution and chemical selectivity of this technique.

Time-gated single photon counting enables separation of CARS microscopy data from multiphoton-excited tissue autofluorescence

“…This is particularly true for chlorophyll-rich plant tissues. Chlorophyll exhibits strong fluorescence with a peak emission at ~ 670 nm, which overlaps with most CARS signals obtained by using a combination of laser wavelengths around 800 nm and 1064 nm as done in most of the current CARS microscopy setups [4,[28][29][30]. Other tissue types, in particular tissues that are in contact with blood, have other sources of broadband autofluorescence in a similar wavelength range, which stem from e.g.…”

Inline holographic coherent anti-Stokes Raman microscopy

“…Holography has also been applied to fluorescence [3,4] and second harmonic [5,6] microscopy which utilize fluorophores or second harmonic nanocrystal markers to provide the contrast. Unlike these imaging modalities, coherent anti-Stokes Raman scattering (CARS) microscopy has been extensively investigated in recent times due to its capability to perform label-free imaging as well as the significantly improved sensitivity of CARS compared to spontaneous Raman scattering [7][8][9][10][11]. We have recently demonstrated a holographic CARS imaging technique which combines the unique ability of both holography and CARS and can perform three-dimensional chemical selective imaging [12].…”

Single-shot hyperspectral coherent Raman planar imaging in the range 0–4200 cm−1

“…Chirped-pulse excitation, 5 with single-shot collection of the spectrum, has been developed partly to speed up the acquisition-time, and holography 6 has been preliminarily explored to circumvent the scanning procedure altogether. Wide-field CARS microscopy has been demonstrated to enable the detection of a two-dimensional (2D) field microns in diameter within a single-laser-shot [7][8][9][10] for a given transition frequency. Recently reported highspeed molecular imaging 11 demonstrated frame-by-frame wavelength tunability with a time window for data collection spanning $30 ms for each frame.…”