In integrated optics, optical waveguides are fundamental elements for the development of integrated devices, including light sources, modulators, detectors, optical pathways, receivers and switches. For the fabrication of optical integrated waveguide components, grating couplers or other complex integrated structures realized on planar optical waveguides, materials with high photorefractivity are surely of great interest since they allow applying photorefractive direct-laser-writing techniques which are of lower cost and less time-consuming than conventional photolithography and etching processes. This chapter provides an overview of classes of photorefractive materials such as photorefractive glasses, glass-ceramics, crystals and polymers, which are promising candidates for integrated optics. Different aspects, including material preparation, photorefractivity investigation and the fabrication of photorefractive direct-laser-written micro/nano-optical structures such as channel waveguides and gratings in each type of photorefractive materials, are also discussed.

Chapter Contents:

• 9.1 Fundamentals of photorefractive waveguides
• 9.1.1 Photorefractivity
• 9.1.2 Integrated optical waveguides
• 9.2 Photosensitive glasses and glass-ceramics
• 9.2.1 Germanosilicate glasses
• 9.2.1.1 Photosensitivity investigation
• 9.2.1.2 Direct UV-laser-written optical structures
• 9.2.2 Tin dioxide–silica glasses and glass-ceramics
• 9.2.2.1 Photosensitivity of tin-doped silica glasses
• 9.2.2.2 Photosensitivity of tin-dioxide-based glass-ceramics
• 9.2.2.3 Direct UV-laser-written micro-optical structures in SiO2–SnO2
• 9.2.3 Chalcogenide glasses
• 9.2.3.1 Photosensitivity investigation
• 9.2.3.2 Direct-laser-written micro-optical structures in ChGs
• 9.2.4 Other photosensitive glasses
• 9.2.4.1 Pyrex borosilicate glasses
• 9.2.4.2 Nd-doped fluoroaluminate glasses
• 9.2.4.3 Bismuth-based silicate glasses
• 9.2.4.4 Lead silicate glasses
• 9.3 Photorefractive crystals
• 9.3.1 Material preparation
• 9.3.2 Photorefractive effects
• 9.3.3 Some examples of photorefractive crystal waveguides
• 9.3.3.1 LiNbO3 waveguides
• 9.3.3.2 LiTaO3 waveguides
• 9.3.3.3 Other photorefractive crystal waveguides
• 9.4 Photorefractive polymers
• 9.4.1 Photorefractive effects
• 9.4.2 Photorefractive polymer waveguides
• 9.5 Summary
• References

Inspec keywords: optical couplers; micro-optics; integrated optics; optical polymers; optical glass; laser materials processing; etching; optical fabrication; nanofabrication; photorefractive effect; diffraction gratings; optical planar waveguides; nanophotonics; photorefractive materials; photolithography; microfabrication; reviews; glass ceramics

Other keywords: overview; photorefractive direct-laser-writing techniques; photorefractive glasses; conventional photolithography; integrated optics; complex integrated structures; integrated devices; receivers; photorefractive materials; switches; grating couplers; glass-ceramics; material preparation; polymers; photorefractive waveguides; channel waveguides; etching processes; fundamental elements; photorefractive direct-laser-written microoptical structures; photorefractive direct-laser-written nanooptical structures; optical integrated waveguide components; light sources; planar optical waveguides

Subjects: Optical materials; Micro-optical devices and technology; Reviews and tutorial papers; resource letters; Integrated optics; Light-sensitive materials; Integrated optics; Optical waveguides and couplers; Laser materials processing; Optical fabrication, surface grinding; Nanophotonic devices and technology; Optical glass; Optical phase conjugation and multiwave mixing; Optical polymers and other organic optical materials; Multiwave mixing; Optical waveguides; Laser materials processing; Micro-optical devices and technology; Nanophotonic devices and technology; Gratings, echelles