High‐speed broadband Fourier‐transform coherent anti‐stokes Raman scattering spectral microscopy

Abstract

We demonstrate broadband Fourier‐transform coherent anti‐Stokes Raman scattering (FT‐CARS) spectral microscopy with a pixel dwell time of 42 μs, which is ~50 times shorter than the shortest‐to‐date pixel dwell time for CARS spectral microscopy. Our broadband FT‐CARS spectral microscope is composed of an FT‐CARS spectrometer, a rapid galvanometric scanner, and a high‐speed image acquisition circuit, enabling a frame rate of 2.4 fps with a pixel resolution of 100 × 100 pixels, a bandwidth of 600–1,200 cm−1, a spatial resolution of 0.95 μm, and a spectral resolution of 37 cm−1. As a proof‐of‐principle demonstration, we used the high‐speed FT‐CARS spectral microscope to perform CARS imaging of polymer beads and Haematococcus lacustris cells. Our high‐speed broadband CARS spectral microscope holds promise for studying rapid cellular dynamics, such as signaling, cell‐to‐cell communication, and molecular transport in a label‐free manner.

Coherent Raman scattering microscopy: capable solution in search of a larger audience

“…In point-scanning CARS microscopy, the Fourier transform approach has produced spectral acquisition times of 42 μs per spatial pixel. 87 A related strategy has also been implemented in a wide-field CARS microscope. 88 Outside of the microscope, even higher spectral acquisition rates have been reached, 89 up to 100;000 spectra∕s in the form of dual-comb coherent Raman spectroscopy.…”

Advanced Label-Free Laser Scanning Microscopy and Its Biological Imaging Application

“…Then a CARSM with imaging speed of video-rate was developed for vibrational imaging of tissues in vivo by Xie's group via detecting strong backscattering of forward CARS signal with video-rate scanning microscopy [15]. Today, higher speed imaging has been achieved by employing more techniques, such as Fourier-transform [16] and deep-learning noise reduction [17]. The spectral bandwidth of CARSM has also shown great increase by multiplex [18,19] and broadband CARSM techniques [20,21].…”

Recent advances in linear and nonlinear Raman spectroscopy. Part XIV

“…Collisional dephasing time constants were obtained from a coherent beating model function. Kinegawa et al [ 104 ] described high‐speed broadband Fourier‐transform CARS spectral microscopy. Their new CARS microscope holds promise for studying rapid cellular dynamics, such as signaling, cell‐to‐cell communication, and molecular transport in a label‐free manner.…”