Evaluation of a gain-managed nonlinear fiber amplifier for multiphoton microscopy

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

We introduce a compact, all-fiber laser system with a gain-managed nonlinear (GMN) amplified Yb:fiber oscillator and an integrated pulse-picker. The system delivers 39 fs pulses with peak powers of 0.83 MW and adjustable pulse repetition rates (0.3-15 MHz), enabling multiphoton imaging at remarkably low excitation powers (as low as 66 µW). Its design simplifies integration and enhances experimental flexibility. Compatible with two- and three-photon excitation, but also second harmonic generation microscopy, this versatile system offers precise control of imaging parameters, making it an effective tool for advancing multiphoton microscopy and other imaging techniques across various experimental environments.

Dissimilar soliton molecule formed by dissipative pulses in a single-mode mode-locked fiber laser

Soliton molecules, or also known as optical bound states, are the most representative example of solitons' particle nature and have given birth to diverse light-matter analogies. Despite detailed research on regular bound states, the soliton molecule synthesis of dissimilar pulses has rarely been reported. Here, soliton molecules formed by dissimilar dissipative solitons are demonstrated in a single-mode mode-locked fiber laser, with an in-depth analysis of their evolution dynamics. This novel bound state features pulse trapping between two ultrafast vector pulses with distinct pulse properties including energy, duration, and chirp, leading to unique temporal and spectral profiles. This laser provides an optimal platform for studying complex interactions between different types of dissipative solitons. The findings here can provide new degrees of freedom for the generation of optical soliton molecules and can fuel applications in optical information processing, metrology, and spectroscopy.

SLAM medical imaging enabled by pre-chirp and gain jointly managed Yb-fiber laser

We demonstrate a pre-chirp and gain jointly managed Yb-fiber laser that drives simultaneous label-free autofluorescence-multiharmonic (SLAM) medical imaging. We show that a gain managed Yb-fiber amplifier produces high-quality compressed pulses when the seeding pulses exhibit proper negative pre-chirp. The resulting laser source can generate 43-MHz, 34-fs pulses centered at 1110 nm with more than 90-nJ energy. We apply this ultrafast source to SLAM imaging of cellular and extracellular components in various human tissues of intestinal adenocarcinoma, lung adenocarcinoma, and liver.