Abstract: A method of crystallising a thin film (220) including the steps of: depositing a thin film (220) on a substrate (210; and exposing the thin film (220) as deposited on the substrate (210) and the substrate (210) to a plasma for a time period of greater than 5 minutes, wherein: the thin film (220) is one of an amorphous magneto optic material, an amorphous electro optic material or a nitride material; a gas (130) is excited with a radio frequency (RF) field to form the plasma; the thin film (220) and the substrate (210) are, in the course of being exposed to the plasma, heated to temperatures of between 400° C. and 550° C. by the plasma; and the thin film (220) is at least partially crystallised by the plasma.

Abstract: A structure (10) for rotating a plane of polarization of a polarized visible light signal, including a lower mirror (13) bonded to a top of a substrate (11) with a first bonding layer (12a), a magneto-optic layer (14) disposed on a top of the lower mirror (13), and an upper mirror (15) disposed on a top of the magneto-optic layer (14); wherein when the structure (10) is annealed the first bonding layer (12a) aids adhesion of the lower mirror (13) to the substrate (11).