Beam scanning for rapid coherent Raman hyperspectral imaging.

Area of Science:

• Microscopy
• Nonlinear Optics
• Spectroscopy

Background:

• Coherent Raman imaging relies on high-peak power lasers for strong nonlinear signals.
• Photo-induced sample damage is a significant limitation in high-power microscopic imaging.

Purpose of the Study:

• To investigate beam scanning as a method to mitigate photodamage in BCARS imaging.
• To assess the impact of beam scanning on signal intensity, spatial resolution, and imaging speed.

Main Methods:

• Implemented a 3.5-kHz resonant mirror for beam scanning in a BCARS system.
• Utilized reflective mirrors to minimize optical aberrations and dispersion.
• Employed slit acquisition for parallel spectral data collection.
• Compared beam-scanning with sample-scanning modes at maximum laser power below the damage threshold.

Main Results:

• Beam scanning significantly reduced photo-induced damage in biological cells and tissues.
• Signal intensity was maintained without compromise.
• Faster imaging speeds were achieved by enabling higher excitation laser power.
• Beam scanning with slit acquisition demonstrated comparable spatial resolution to sample scanning.

Conclusions:

• Beam scanning is an effective strategy for reducing photodamage in BCARS microscopy.
• This method enhances imaging speed and allows for higher laser power utilization.
• The technique is suitable for sensitive biological imaging applications.