Polymer-Based Optical Waveguides

Abstract

Polymer optical waveguides would play a key role in broadband communications, such as optical networking, metropolitan access communications, and computing systems, due mainly to their easier processibility and integration over inorganic counterparts. The combined advantages also make them an ideal integration platform where foreign material systems, such as yttrium iron garnet and lithium niobate, as well as semiconductor devices such as lasers, detectors, amplifiers, and logic circuits can be inserted into an etched groove in a planar lightwave circuit to enable full amplifier modules or optical add/drop multiplexers on a single substrate. Moreover, the combination of flexibility and toughness in optical polymers makes it suitable for vertical integration to realize 3D and even all-polymer integrated optics. This chapter would provide a brief review about polymer-based optical waveguides, including suitable polymer waveguide systems, their processing and fabrication techniques, and the integrated optical waveguide components and circuits derived from these materials. Rationale of Polymers Used for Optical WaveguidesAs discussed in previous chapters, depending on the phenomenon of total internal reflection guided wave optics can confine light in the optical waveguide, a material surrounded by other materials with lower refractive indices. Optical waveguides may be thin-film deposits used in integrated optical circuits or a filament of dielectric material usually circular in the cross section used in fiber optics. Depending on various possible patterns or propagating or standing electromagnetic fields, there are single-mode and multi-mode optical waveguides. Each mode is characterized by its frequency, effective refractive index, polarization, power distribution, electric field strength, and magnetic field strength.With the rapid advance of integrated optics, the importance of optical waveguides, which are the fundamental elements of optical integrated circuits (ICs), has been widely recognized. For example, the further success of broadband X.C. Tong, Advanced Materials for Integrated Optical Waveguides, Springer Series in Advanced Microelectronics 46, DOI 10.1007/978-3-319-01550-7_9, © Springer International Publishing Switzerland 2014 377 communications in optical networking, metro/access communications, and computing will rely on the advancement of optical interconnects, optical components, such as splitters, combiners, multiplexers, and demultiplexers, optical switches/modulators, tunable filters, variable optical attenuators (VOAs), amplifiers, and integrated optical circuits that are based on optical waveguides. While the basic technologies for the design and production of many integrated optical waveguide devices are in place, a great many materials have also been developed. Today, glass optical fibers are routinely used for high-speed data transfer. Although these fibers provide a convenient means for carrying optical information over long distances, they are inconvenient for complex high-density...

Fabrication of Sub-Micron Polymer Waveguides through Two-Photon Polymerization in Polydimethylsiloxane

“…The development of new materials and novel fabrication technologies for the realization of optical waveguides have attracted great attention. In particular, polymer-based waveguides are crucial soft photonic building blocks [3][4][5] for the development of complex multifunctional platforms, such as chip-to-chip interconnects in electronic systems [6,7], lab-on-chips [8], optofluidic platforms [9], biomedical sensing [10,11], wearable physiological monitoring [12], and optogenetics [13][14][15]. Single-mode optical waveguides have been fabricated through direct laser writing (DLW), soft lithography, and thermal curing methods using poly-siloxane and other commercially available polymer materials [16][17][18][19].…”