Pulse-to-pulse wavelength switchting of diode based fiber laser for multi-color multi-photon imaging

TL;DR

This paper introduces a fiber-based laser system capable of rapidly switching wavelengths for multi-color multi-photon imaging, utilizing nonlinear effects to extend the spectral range of diode lasers for bio-imaging applications.

Contribution

It presents a novel all-fiber laser setup that achieves pulse-to-pulse wavelength switching through nonlinear effects, enabling versatile multi-color imaging without changing the system configuration.

Findings

First demonstration of two-photon imaging with shifted wavelengths.

Pulse-to-pulse wavelength switching achieved without system reconfiguration.

Enhanced spectral range of diode lasers for bio-imaging applications.

Abstract

We present an entirely fiber based laser source for non-linear imaging with a novel approach for multi-color excitation. The high power output of an actively modulated and amplified picosecond fiber laser at 1064 nm is shifted to longer wavelengths by a combination of four-wave mixing and stimulated Raman scattering. By combining different fiber types and lengths, we control the non-linear wavelength conversion in the delivery fiber itself and can switch between 1064 nm, 1122 nm, and 1186 nm on-the-fly by tuning the pump power of the fiber amplifier and modulate the seed diodes. This is a promising way to enhance the applicability of short pulsed laser diodes for bio-molecular non-linear imaging by reducing the spectral limitations of such sources. In comparison to our previous work [1, 2], we show for the first time two-photon imaging with the shifted wavelengths and we demonstrate pulse-to-pulse switching between the different wavelengths without changing the configuration.