Dual-comb photoacoustic spectroscopy

Area of Science:

• Optics
• Spectroscopy
• Biomedical Imaging

Background:

• Spectrally resolved photoacoustic imaging offers label-free visualization in scattering media.
• Current methods are slow, requiring separate measurements per wavelength, risking sample changes.
• This limitation hinders real-time imaging applications.

Purpose of the Study:

• To introduce a novel method for high-speed, spectrally resolved photoacoustic measurements.
• To overcome the speed and accuracy limitations of conventional wavelength-by-wavelength acquisition.
• To demonstrate a proof-of-concept for simultaneous multi-wavelength photoacoustic analysis.

Main Methods:

• Utilized dual-comb spectroscopy for photoacoustic measurements.
• Interfered two optical-frequency combs on polymer film samples.
• Measured acoustic pressure waves with an ultrasound transducer and processed signals in the frequency domain.

Main Results:

• Achieved simultaneous photoacoustic measurements across thousands of wavelengths.
• Obtained optical absorption spectra that closely matched spectrophotometer results.
• Demonstrated the feasibility of dual-comb spectroscopy for photoacoustic analysis.

Conclusions:

• Dual-comb spectroscopy significantly enhances photoacoustic imaging speed by acquiring data across numerous wavelengths simultaneously.
• This technique provides accurate spectral information, comparable to traditional methods.
• Future improvements in signal-to-noise ratio could unlock high-speed, spectrally resolved photoacoustic imaging capabilities.