Divided-aperture confocal Brillouin microscopy for simultaneous high-precision topographic and mechanical mapping

Area of Science:

• Optics and Photonics
• Materials Science
• Biophysics

Background:

• Confocal Brillouin microscopy (CBM) offers non-contact mechanical property analysis.
• Conventional CBMs face limitations in depth of focus and system stability, hindering high-precision mapping.
• Applications span biological tissue, cell imaging, and manufacturing material characterization.

Purpose of the Study:

• To develop a divided-aperture confocal Brillouin microscopy (DCBM) technique.
• To enhance axial focusing capability, system stability, and extinction ratio of CBM.
• To enable in situ topographic and mechanical mapping of samples.

Main Methods:

• Implementation of a divided-aperture confocal optical setup.
• Utilizing high-sensitivity divided-aperture confocal technology for axial focusing.
• Incorporating a dark-field configuration to improve the extinction ratio.

Main Results:

• Achieved a 100-fold enhancement in axial focusing sensitivity, reaching 5 nm.
• Significantly improved system stability for long-term measurements.
• Enhanced the extinction ratio by 20 dB using a dark-field setup.

Conclusions:

• The proposed DCBM technique overcomes limitations of conventional CBMs.
• DCBM enables unprecedented precision in micro-mechanical property mapping.
• This method offers a novel approach for in situ topographic and mechanical imaging in Brillouin scattering applications.