Abstract

Ultrafast laser systems operating around 1.7 µm to 1.8 µm are powerful tools to extend the penetration depth of mulitphoton microscopes [1, 2]. However, radiation at this wavelength region is not readily available and thus frequency shifting was necessary to obtain the desired wavelength. Here, we demonstrate an ultrafast thulium-doped fiber laser system generating the spectrum covering the 1.8 µm region, whose output pulses have sufficient intensity for three-photon excitation necessary for multiphoton microscopes.

© 2019 IEEE