Distortion-free delivery of nanojoule femtosecond pulses from a Ti:sapphire laser through a hollow-core photonic crystal fiber.
We demonstrate propagation of femtosecond pulses in the 800-nm range through a hollow-core photonic crystal fiber with preserved temporal and spectral profiles for pulse energies up to 4.6 nJ. Without the use of a prechirping unit, 170-fs pulses were transmitted essentially undistorted at 812 nm, near the zero-dispersion wavelength. Because of the air guidance of pulses, intensity-dependent nonlinear effects were minimal, with only 15% pulse broadening occurring at 350-mW average output power. This fiber thus is excellently suited for applications that require single-mode delivery of high-energy ultrashort pulses to the fiber output face such as, for example, miniaturized multiphoton microscopes.
Göbel
Werner
W
Max-Planck-Institut für medizinische Forschung, Johnstrasse 29, 69120 Heidelberg, Germany.
Nimmerjahn
Axel
A
Helmchen
Fritjof
F