A Polycrystalline Fiber Optic with Coupler Designed for Free-Moving Animals

Polycrystalline fiber optic cannulas are used to irradiate different parts of the brain region after stereotaxic positioning of the brain in animals and play an important role in animal in vivo experiments. However, during the insertion and removal of the fiber optic, the animal and the fiber optic are susceptible to varying degrees of damage, and the optical fiber inevitably reduces the transmission efficiency. Here, we designed a new buried polycrystalline fiber optic cannula to solve the problem of frequent insertion and withdrawal of the fiber optic and other problems arising from the use of optical fibers. This polycrystalline fiber optic cannula uses a screw-tightening method to complete the coupling. We found that this design not only improved the speed of fiber insertion and reduces fiber loss, but also allows the THz waves to be delivered while the animal is fully awake, thus recording the animal's behavior and other relevant experimental data in real time. In summary, this design prolongs the service life of the fiber optics itself and provides more possibilities for subsequent in vivo animal experiments.