Feasibility Analyses and Experimental Confirmation of Dove Prism Based Dual-fiberscope Rotary Joint

Two-photon fluorescence microscopy has enjoyed its wide adoption in neuroscience. Head-mounted miniaturized fiberscopes offered an exciting opportunity for enabling neural imaging in freely-behaving animals with high 3D resolution. Here we propose a dual-fiberscope rotary joint based on a Dove prism, for enabling simultaneous two-photon imaging of two brain regions with two fiberscopes in freely-walking/rotating mice. Analytic proof has confirmed the key properties of a Dove prism. Feasibility analyses and proof-of-concept experimental results have demonstrated the feasibility of such a rotary joint for allowing two fiberscopes to rotate simultaneously while maintaining an excellent single-mode fiber-to-fiber coupling for the excitation femtosecond laser. Fiberscopes with a dual-probe rotary joint offer an exciting opportunity to explore neural network dynamics of multiple interconnected brain regions in freely-walking rotating animals.