Single-cavity dual-wavelength all-fiber femtosecond laser for multimodal multiphoton microscopy.

A single-cavity dual-wavelength all-fiber femtosecond laser is designed to generate 1030 nm wavelength for high resolution multiphoton imaging and 1700 nm wavelength for long penetration depth imaging. Considering two-photon and three-photon microscopy (2PM and 3PM), the proposed laser provides the single-photon wavelength equivalent to 343 nm, 515 nm, 566 nm and 850 nm, that can be employed to excite a wide variety of intrinsic fluorophores, dyes, and fluorescent proteins. Generating two excitation wavelengths from a single laser reduces the footprint and cost significantly compared to having two separate lasers. Furthermore, an all-reflective microscope is designed to eliminate the chromatic aberration while employing two excitation wavelengths. The compact all-fiber alignment-free laser design makes the overall size of the microscope appropriate for clinical applications.