Bragg grating and method of producing a bragg using an ultrafast laser

摘要

A novel Bragg grating filter (46) in optical waveguiding fiber (43) with suppressed cladding mode coupling and method of producing same is disclosed. The novel grating structure (46) is induced in both the core (45) and the cladding (44) of the optical fiber irrespective of the photosensitivity of the core or cladding to actinic radiation. Such core and cladding of the optical fiber need not be chemically doped to support the grating. The method incorporates an ultra short duration pulse laser source. Electromagnetic radiation (40) provided from the laser propagates to a diffractive element (42) positioned a specific distance (47) to the target material such that the diffracted electromagnetic radiation forms a 2-beam interference pattern, the peaks of which are sufficiently intense to cause a change in index of refraction.