Zheltikov integrates NV-diamond magnetometry into photonic-crystal fibers for high-resolution, fiber-delivered magnetic-field imaging and endoscopy, alongside ultrafast biophotonics (multiphoton deep-tissue imaging, SWIR probes) and quantum-light molecular spectroscopy. In the broader landscape of NV-centre ensemble quantum sensing (DEER, nano-NMR, T1 relaxometry) operating near pT/sqrt(Hz) sensitivity, this work extends NV ensemble sensing into fiberized, in-vivo-compatible geometries.