Continuous spatial self-cleaning in GRIN multimode fiber for self-referenced multiplex CARS imaging.

Area of Science:

• Optics and Photonics
• Spectroscopy
• Materials Science

Background:

• Multiplex coherent anti-Stokes Raman Scattering (M-CARS) spectroscopy is a powerful chemical imaging technique.
• Traditional M-CARS setups often require complex optical arrangements for pump and Stokes wave synchronization.

Purpose of the Study:

• To demonstrate the direct application of spatial beam self-cleaning and supercontinuum generation in graded-index multimode optical fibers for M-CARS.
• To explore the potential for self-referenced M-CARS without additional delay lines.

Main Methods:

• Utilizing spatial beam self-cleaning in graded-index multimode optical fibers.
• Employing supercontinuum generation within these fibers for M-CARS.
• Implementing a simplified M-CARS scheme leveraging fiber-based light properties.

Main Results:

• Demonstrated successful application of self-cleaning and supercontinuum generation in M-CARS.
• Observed partial recovery of pump brightness due to self-cleaning, enabling self-referenced M-CARS.
• Presented proof-of-principle imaging of single chemical compounds and polystyrene beads.

Conclusions:

• Spatial beam self-cleaning and supercontinuum generation in multimode fibers offer a simplified approach to M-CARS.
• The proposed scheme paves the way for more accessible and robust M-CARS systems.
• This advancement could lead to broader adoption of M-CARS in various scientific fields.