Optical fiber filter of wideband deleterious light and uses thereof

An optical fiber path for transporting a light beam having a useful component and a deleterious component, the optical fiber path comprising:

• a core carrying the light beam and having a longitudinal propagation axis;
• at least one cladding surrounding the core;
• and
• first and second Fiber Bragg Gratings (FBGs) cascaded along said core, each FBG having an input end and an output end and being disposed along the optical fiber path to receive the light beam along a core mode at the input end, each of the first and second FBGs having a refractive index modulation profile designed to allow the useful component of the light beam to propagate to the output end while coupling the deleterious component into a counter-propagating cladding mode, each of the first and second FBGs defining slanted grating fringes having a tilt angle, the second FBG being rotated by about 90 degrees with respect to the first FBG about an axis of rotation coinciding with the propagation axis in order to minimize polarization dependencies.