Electro-Optic Waveguides
Abstract
Electro-optic waveguides are designed based on changing refractive index of the core layer with an external voltage. Materials used for electro-optic waveguides can be LiNbO3, LiTaO3, BaTiO3, electro-optic polymers, liquid crystal, and strained silicon. The LiNbO3 is a versatile material and used for various applications in guided wave optics, electro-optics, acousto-optics, and nonlinear optics. It has high electro-optic coefficient, optical damage resistance, and low losses. Stoichiometric lithium tantalate is good for applications at UV wavelengths as it is transparent down to 260 nm where most of the standard electro-optical materials, e.g., LiNbO3 or KNbO3, show large light absorption. The optical ferroelectrics in the form of highly transparent thin films are promising materials for communication. BaTiO3 is particularly an attractive candidate for thin film electro-optic modulators due to its large electro-optical coefficients, its high optical transparency and its favorable growth characteristics. Electro-optic (EO) polymers are unique materials having many advantages over inorganic materials for the wide range of applications from optical network components and optical interconnects to millimeter and microwave photonics. They have very large EO coefficients, low optical loss, and low dispersion of refractive index between optical frequencies and millimeter waves, as well as high bandwidth. They are easy to process and have relatively low cost. There is a broad range of EO devices that can be fabricated based on EO polymers having a waveguide structure as the main building block. Liquid-crystal electro-optic waveguide platform has exhibited unprecedented electro-optical phase delays, with very low loss and rapid response time. This technology is based upon a unique liquid-crystal waveguide geometry, which exploits the tremendous electro-optic response of liquid crystals while circumventing historic limitations of liquid crystals. The exceedingly large optical phase delays accessible with this technology enable the design and construction of a new class of previously unrealizable photonic devices. Strained silicon can be another electro-optic material. A significant linear electro-optic effect can be induced in silicon by breaking the crystal symmetry. The strain-induced linear electro-optic effect may be used to remove a bottleneck in modern computers by replacing the electronic bus with a much faster optical alternative. This chapter will give a brief review about various types of electro-optic waveguides, and their materials selection, optimum designs, as well as processing technologies depending on applications.
Keywords
Lithium Niobate Lithium Niobate Crystal Slot Waveguide Photonic Crystal Waveguide Strained SiliconReferences
- Bhandare S (2003) Application of lithium niobate-based integrated optical circuits to optical communication. PhD diddertation, University of Paderborn, Paderborn, GermanyGoogle Scholar
- Castaldini D (2006) Study, fabrication and characterization of segmented waveguides for advanced photonics components on Lithium Niobate. PhD dissertation, Universita di BolognaGoogle Scholar
- Dalton LR (2002) Nonlinear optical polymetic materials: from chromophore design to commercial applications. Adv Polym Sci 158:1–86CrossRefGoogle Scholar
- Das B (2003) Integrated optical distributed Bragg reflector and distributed feedback lasers in Er:LiNbO3 waveguides with photorefractive gratings. Ph.D dissertation, University of Paderborn, GermanyGoogle Scholar
- Davis SR et al (2008) A new electro-optic waveguide architecture and the unprecedented devices it enables. Proc SPIE 6975:1–12Google Scholar
- Davis SR et al (2010) Liquid crystal waveguides: new devices enabled by > 1000 waves of optical phase control. In: Liang-Chy Chien (ed) Liquid crystal technologies V. Proc of SPIE, vol 7618, 76180E, pp 1–14Google Scholar
- Davis AA (2010) Design and analysis of a poled-polymer electro-optic modulator with a strip-loaded waveguide structure. PhD dissertation, University of Dayton, Dayton, OHGoogle Scholar
- Dittrich P et al (2004) Deep-ultraviolet interband photorefraction in lithium tantalite. J Opt Soc Am B 21(3):632–639ADSCrossRefGoogle Scholar
- Fellers TJ, Davidson MW (2012) Acousto-optic tunable filters (AOTFs). http://www.olympusmicro.com/primer/techniques/confocal/aotfintro.html.Accessed03/07/2013
- Fujii Y, Otsuka Y, Ikeda A (2007) Lithium niobate as an optical waveguide and its application to integrated optics. IEICE Trans Electron E90-C(5):1081–1089CrossRefGoogle Scholar
- Iodice M (2003) Transient analysis of a high-speed thermo-optic modulator integrated in an all-silicon waveguide. Opt Eng 42(1):169–175ADSCrossRefGoogle Scholar
- Irvine SE, Elezzabi AY (2003) Wideband magneto-optic modulation in a bismuth-substituted yttrium iron garnet waveguide. Opt Commun 220(4):325–329ADSCrossRefGoogle Scholar
- Jacobsen RS (2006) Strained silicon as a new electro-optic material. Nature 441:199–202ADSCrossRefGoogle Scholar
- Juvalta F (2008) Light-induced waveguides, waveguide arrays and switches in photorefractive LiTO3 and Sn2P2S6. PhD dissertation, ETH Zurich, SwitzerlandGoogle Scholar
- Li GL, Yu PKL (2003) Optical intensity modulators for digital and analog applications. J Lightwave Technol 21(9):2010–2030ADSCrossRefGoogle Scholar
- Nguimdo RM (2008) Optical communications using chaotic carriers generated by electro-optical feedback devices. Master thesis, Universitat de les Illes Balears, PalmaGoogle Scholar
- Petraru AI (2003) Optical and electro-optical properties of BaTiO3 thin films and Mach-Zehnder waveguide modulators. PhD dissertation, Der Universitat KolnGoogle Scholar
- Pyayt AL (2011) Guiding light in electro-optic polymers. Polymers 3:1591–1599CrossRefGoogle Scholar
- Pyayt A, Luo J, Jen AK, Dalton L, Chen A (2010) Field-induced guiding optical devices made from electro-optic polymers. Appl Opt 49:892–896ADSCrossRefGoogle Scholar
- Reed GT, Knights AP (2004) Silicon photonics: an introduction. Wiley, EnglandCrossRefGoogle Scholar
- Selah BEA, Teich MC (2007) Fundamentals of photonics, 2nd edn. Wiley, New YorkGoogle Scholar
- Singh G, Yadav RP, Janyani V (2010) Ti indiffused lithium niobate (Ti:LiNbO3) Mach-Zehnder interferometer all optical switches: a review. In: Aleksandar Lazinica (ed) New advanced technologies, INTECH Publication, Austria, pp 311–322Google Scholar
- Sohler W et al (2005) Erbium-doped lithium niobate waveguide lasers. IEICE Trans. Electron. E88-C (5):990–997CrossRefGoogle Scholar
- Zhou Q (2004) Electro-optic modulators based on polymeric Y-fed directional couplers. PhD dissertation, The University of Texas at AustinGoogle Scholar