Abstract: The present disclosure relates to an optical fiber with shaped photosensitivity profile, comprising a nanostructured core composed of at least two types of glass rods, wherein at least one type of glass rods is doped with germanium. The invention relates also to a method for preparing an optical fiber with a core allowing for obtaining photoinduced refractive index modulation. Depending on their specific type, such optical fibers are applicable i.a. in laser generation and in amplification techniques (active optical fibers) and/or in optical fiber sensors and telecommunications applications (passive optical fibers).