Abstract: A method of inducing refractive index modifications in ferroelectric materials through the application of light in the form of scanned or patterned irradiation, removing the light to leave a permanent refractive index modified structure. This method can be used to design and engineer surface or near-surface structures in the form of waveguides, junctions, splitters and couplers, for application in optical circuitry, integrated optics, and active waveguide devices.

Abstract: A method of inducing a periodic variation of nonlinearity in a sample of ferroelectric material, comprises applying an electrically insulting mask to surface of the sample, applying an electric field across the sample to produce domain inversion in the sample, and removing the electric field when non-inverted regions of the sample remain only in the vicinity of the surface of the sample beneath parts of the surface covered by the mask. This method can be used to engineer accurate domain periods of submicron dimensions or larger which are confined to a surface region of the ferroelectric material, so that the poled material can be used to fabricate planar waveguide devices for nonlinear optical applications. In particular, the submicron periods can be exploited in the fabrication of one and two-dimensional photonic band gap devices.

Abstract: A method of micro-structuring a surface of a sample of ferroelectric material, the method comprising: (a) taking a sample of ferroelectric material having a −z face which is to be etched; (b) illuminating the −z face with ultraviolet light to define illuminated and unilluminated parts of the surface; and (c) immersing the −z face in an etchant to selectively remove the unilluminated parts of the −z face at a greater rate than the illuminated parts. The method can be carried out using pulsed ultraviolet light to etch lithium niobate crystals cut for etching on the −z face, and may further be combined with ablation to produce multi-level surface structures.

Abstract: A method of micro-structuring a surface of a sample of ferroelectric material, the method comprising: (a) taking a sample of ferroelectric material having a −z face which is to be etched; (b) illuminating the −z face with ultraviolet light to define illuminated and unilluminated parts of the surface; and (c) immersing the −z face in an etchant to selectively remove the unilluminated parts of the −z face at a greater rate than the illuminated parts. The method can be carried out using pulsed ultraviolet light to etch lithium niobate crystals cut for etching on the −z face, and may further be combined with ablation to produce multi-level surface structures.