Advances of Mode‐Locking Fiber Lasers in Neural Imaging.

Nonlinear optical microscopy (NOM) has been widely adopted in neural imaging in vivo for its advantages in deep penetration, three‐dimensional resolution, and low phototoxicity, etc. However, it relies on femtosecond laser sources for signal excitation, which are complex and bulky for conventional solid‐state ultrafast lasers. Alternatively, the development of mode‐locking fiber lasers has successfully promoted their applications in biomedical imaging. This paper focuses on the advances of mode‐locking fiber lasers in neural imaging, based on both multiphoton fluorescence microscopy and parametric NOM. Fiber laser oscillators are summarized for exciting two‐photon microscopy directly and fiber lasers based on nonlinear frequency shifting for exciting three‐photon microscopy. Besides, the applications of mode‐locking fiber lasers in parametric NOM are briefly introduced, including harmonic generation microscopy and coherent Raman microscopy. Moreover, the potentials of mode‐locking fiber lasers are highlighted in two‐photon optogenetics for neural modulation. With the emerging of novel high‐energy fiber lasers, their widespread applications are expected in the study of neuroscience. [ABSTRACT FROM AUTHOR]