2-in-1 Dual-Fiber Probe Integrated With Nanodiamonds for Optical Thermometry Measurements

We here propose and demonstrate a novel “2-in-1” fiber consisting of two freely separated fiber ends and one fiber tip mounted with nanodiamonds (NDs) containing nitrogen vacancy (NV) centers. The fiber tip with ball lens is fabricated by fusing two parallel multimode fiber with arcing discharge. The excitation and collection of the integrated NV centers through the two fiber ends, can be optimized by manipulating the fabricated lens. We also demonstrate the feasibility of all-optical thermometry using this device. This endoscopy-like probe paves the way for developing fiber-based quantum device for flexible thermometry and magnetometry.