Increasing Brightness in Multiphoton Microscopy with Low-Repetition-Rate, Wavelength-Tunable Femtosecond Fiber Laser

Multiphoton microscopy uses nonlinear interaction with the sample as a contrast mechanism and is becoming widespread in biomedical sciences. The development of this technique and its applications requires more sophisticated and agile femtosecond laser sources. The most demanding applications, such as neurology or ophthalmology, require precisely adjusted excitation laser parameters. This helps to increase penetration depth, improve contrast, or reduce phototoxicity [1], [2]. We propose a compact, fiber-based femtosecond laser with an adjustable pulse repetition rate and output wavelength in this work. We show that both features can be used to increase the brightness of images in multiphoton microscopy.