Multiphoton microscopy at a microwatt level via gain-managed nonlinear amplification and pulse-picking

Area of Science:

• Biophotonics and Imaging
• Laser Physics and Engineering

Background:

• Multiphoton microscopy requires advanced laser systems for high-resolution imaging.
• Existing systems can be bulky, complex, and require high excitation powers.
• Need for versatile, compact, and low-power laser sources for broader accessibility.

Purpose of the Study:

• To introduce a novel, compact, all-fiber laser system for advanced imaging techniques.
• To demonstrate its capability for multiphoton imaging at significantly reduced excitation powers.
• To enhance experimental flexibility and integration in various microscopy setups.

Main Methods:

• Development of a gain-managed nonlinear (GMN) amplified Yb:fiber oscillator.
• Integration of a pulse-picker for adjustable repetition rates (0.3-15 MHz).
• Characterization of ultrashort pulse generation (39 fs) and peak power (0.83 MW).

Main Results:

• The laser system delivers ultrashort pulses with high peak power.
• Enables multiphoton imaging at excitation powers as low as 66 µW.
• Demonstrates compatibility with two-photon, three-photon, and second harmonic generation microscopy.

Conclusions:

• The compact all-fiber laser system offers a versatile and efficient solution for advanced microscopy.
• Low excitation power requirements make it suitable for sensitive biological samples.
• The system's design simplifies integration and expands applications in biophotonics.