Abstract: A method of designing a multi-channel grating structure in a waveguide material, the method comprising the step of utilising a multi-channel grating design function describing an envelope of a refractive index variation defining the multi-channel grating structure in the waveguide material, wherein the multi-channel grating design function deviates from a periodic sampling function multiplied by a single channel grating design function.

Abstract: A packaging device (10) for an optical fibre (24) is disclosed, the device comprising a first material member (12), a second material member (14), at least one lever arm (16) connectable to the fibre (24), and amounting assembly (18, 20) for rotatably mounting the lever arms (16) to at least one of the first and/or second material members, the lever arm (16) being arranged, in use, to operate under temperature induced relative movement of the first and second material members in a manner such that strain in the fibre (24) is controlled to compensate for a temperature induced change in an optical property of the fibre (24). The mounting assembly (18, 20) may include a cylindrical axis member, one or more bearing balls, or one or more protrusions or indentations formed on the lever arm (16) and at least one of the first and/or second material members.

Abstract: A method of operational tuning of an optical structure, such as a Bragg grating, incorporated in an optical waveguide (24) mounted in a packaging device (10) is disclosed. The method comprises the steps of applying a transverse compressive load (33) to a first longitudinal member (12) of the packaging device (10), the load (33) being above a non-elastic deformation threshold of the first material member (12), to achieve a longitudinal expansion (37) of the first material member (12). The longitudinal expansion (37) results in the tuning being affected through a lever mechanism operating under relative movement of the first material member (12) and a second material member (14) of the packaging device (10).