Few-cycle all-fiber supercontinuum laser for ultrabroadband multimodal nonlinear microscopy.

Area of Science:

• Optics and Photonics
• Biomedical Imaging

Background:

• Few-cycle light pulses are crucial for nonlinear optics and spectroscopy.
• Bulk crystal-based sources are often complex and costly.
• Fiber-optic solutions offer potential for more robust and efficient pulse generation.

Purpose of the Study:

• To present a monolithic fiber-optic configuration for generating transform-limited, temporally coherent supercontinuum pulses.
• To demonstrate the utility of these pulses in biological imaging applications.

Main Methods:

• Utilizing self-phase modulation and optical wave breaking in an all-normal dispersion photonic crystal fiber.
• Pumping the fiber with high-energy, hundreds-of-femtosecond duration pulses from an all-fiber chirped pulsed amplification system.
• Developing a monolithic, all-fiber configuration to avoid free-space propagation.

Main Results:

• Generation of transform-limited, temporally coherent supercontinuum pulses with a central wavelength of 1.06 µm.
• Achieved pulse durations as short as 13.0 fs (3.7 optical cycles).
• Demonstrated robust, efficient, and cost-effective operation due to the monolithic design.

Conclusions:

• The all-fiber few-cycle pulsed source is a powerful tool for applications requiring ultrabroadband spectra and ultrashort pulse durations.
• The system's deep light penetration in biological tissues at 1 µm enables successful ultrabroadband nonlinear microscopy.
• This configuration provides an attractive alternative to bulk crystal-based sources.