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Since the first demonstration of electric field poling in 1993 - by workers at Sony - periodically poled materials (e.g. PPLN) have become ubiquitous in photonics. Their ability to allow quasi-phase matching opens up nonlinear optics across the full transparency bands of a material. In the case of PPLN this spans from the visible out to around 5 microns – offering a powerful route to create light in spectral regions where convenient lasers do not exist. This talk will cover underlying physics, materials, design, manufacturing and applications, as well as looking at next generation applications.

This talk will describe the fabrication of periodically poled lithium niobate non-linear waveguides for the emerging quantum technology industry. It will address the challenges of optical engineering high-efficiency frequency conversion devices for the field and their application.

Intracavity second-harmonic generation of 1.56 and 1.52 W continuous-wave 532 nm green laser radiation was obtained by quasi-phase matching in periodically-poled MgO:LiNbO3 (MgO:PPLN) crystals with lengths of 2 and 1 mm, respectively. The maximum optical-to-optical efficiency achieved was 52%. The intracavity temperature bandwidth was 15 and 12°C for 1 mm crystal and 2 mm crystal, respectively. [ABSTRACT FROM AUTHOR]

We report on the fabrication of bidimensional arrays of hexagonal domains with strictly periodic and quasi-periodic patterns for the implementation of nonlinear photonic crystals and quasi-crystals in z-cut congruent LiNbO3. [ABSTRACT FROM AUTHOR]

The article presents a direct grating writing technique that allows simultaneous ultraviolet (UV) definition of channel wave guides with integral Bragg gratings in a photosensitive planar media. Based on a small-spot interference pattern generated by two focused UV-writing beams, the single-step approach was developed to promote optimal use of sample photosensitivity for both the wave guide geometry and Bragg grating superstructure, with the potential for implementing many aspects of advanced grating design, such as chirp and apodisation, without the need for a phase mask.

An integrated direct UV written apodised planar Bragg grating reflector with 154 GHz (1.23 nm) of thermo-optic tuning in the C-band and a response speed 31 GHz/ms is demonstrated. The degree and speed of tuning of the fabricated device indicates potential application in dynamic optical networks, as an optical add-drop multiplexer. [ABSTRACT FROM AUTHOR]

A method for fabricating planar silica substrates via modified chemical vapour deposition (MCVD) and a modified fibre drawing technique is presented. Long lengths of planar material are generated from a single substrate offering a potentially low-cost alternative to existing planar substrate deposition processes. Buried straight and splitting waveguide channels, as well as Bragg gratings, are inscribed in the planar material using direct UV-writing technology, and the results are reported. [ABSTRACT FROM AUTHOR]

A single-step ductile dicing process capable of manufacturing optical quality facets in lithium niobate (LiNbO3) ridge waveguides with an average surface roughness of 0.29 nm is reported. This result is comparable with surface roughnesses achieved by lapping and polishing and represents an order of magnitude improvement over the prior state of the art in LiNbO3 waveguide facet dicing. [ABSTRACT FROM AUTHOR]