Broadband coherent Raman spectroscopy based on single-pulse spectral-domain ghost imaging.

Area of Science:

• Spectroscopy
• Chemical Sensing
• Vibrational Imaging

Background:

• Coherent Anti-Stokes Raman Scattering (CARS) spectroscopy is crucial for chemical sensing and label-free vibrational imaging.
• Conventional CARS methods face limitations in acquisition speed and detection complexity.

Purpose of the Study:

• To demonstrate a high-speed broadband CARS technique.
• To overcome limitations of conventional CARS methods for faster chemical analysis and imaging.

Main Methods:

• Utilized nonlinear spectral ghost imaging combined with time-stretch dispersive Fourier-transform (TS-DFT) spectroscopy.
• Employed modulation instability for stochastic supercontinuum generation (Stokes) and synchronized narrowband pulses (pump).
• Captured reference Stokes spectra via TS-DFT and anti-Stokes signals with a single photodetector.

Main Results:

• Achieved broadband CARS spectral reconstruction across fingerprint and C-H stretching regions.
• Obtained 13 cm^-1 spectral resolution with microsecond-scale acquisition times.
• Demonstrated robust signal recovery without spectral resolution in the detection path.

Conclusions:

• The developed method significantly enhances CARS acquisition speed.
• Enables robust CARS measurements in complex biological and chemical settings.
• Facilitates advanced label-free chemical sensing and vibrational imaging applications.