Simultaneous label-free autofluorescence-multiharmonic microscopy driven by femtosecond sources based on self-phase modulation enabled spectral selection

Nonlinear optical microscopy techniques have unique advantages in tissue imaging, such as enhanced contrast, high resolution, label-free deep sectioning capabilities and so on. also has multiple imaging modalities, corresponding to various components biological tissues. Unfortunately, its wide applications are hindered due the lack of broadly tunable femtosecond sources designed for driving multimodalities simultaneously. To solve this challenge, we proposed a new wavelength conversion approach——self-phase modulation (SPM) enabled spectral selection, dubbed SESS. SESS employs SPM broaden input spectrum short fiber, broadened features well-isolated lobes. Using suitable filters select outermost lobes produces nearly transform-limited pulses. In paper, demonstrate fiber-optic source multimodal nonlinear microscopy. Based on 43-MHz Yb-fiber laser, can emit 990-nm, 84-fs pulses with 5-nJ energy pulse duration; it produce 1110-nm, 48-fs 15-nJ energy. The 990-nm used drive two-photon excitation fluorescence many important fluorophores second-harmonic generation microscopy, which, combined image splicing technology, enables us obtain large field view gastric tissue. We employ 1110-nm simultaneous autofluorescence-multiharmonic Two-photon fluorescence, three-photon third-harmonic signals simultaneously excited efficiently. Such driven by constitutes powerful tool biomedical imaging.