Guided-Wave Acousto-Optics: Interactions, Devices, and Applications

ISBN-13: 9783642752278 / Angielski / Miękka / 2011 / 322 str.

Chen S. Tsai

Opis

The field of integrated- or guided-wave optics has experienced significant and continuous growth since its inception in the late 1960s. There has been a considerable increase in research and development activity in this field worldwide and some significant advances in the realization of working in tegrated optic devices and modules have been made in recent years. In fact, there have already been some commercial manufacturing and technical ap plications of such devices and modules. The guided-wave-acoustooptics involving Bragg interactions between guided optical waves and surface acoustic waves is one of the areas of in tegrated-optics that has reached some degree of scientific and technological maturity. This topical volume is devoted to an in-depth treatment of this emerging branch of science and technology. Presented in this volume are concise treatments on bulk-wave acoustooptics, guided-wave optics, and surface acoustic waves, and detailed studies of guided-wave acoustooptic Bragg diffraction in three promising material substrates, namely, LiNb0, 3 ZnO/Si0, and GaAs, the resulting wide band modulators and deflectors, 2 and applications. The chapters cover not only the basic principles and the oretical analysis, but also the design, fabrication, and measurement of the resulting devices and modules, and their applications."

Spis treści

1. Introduction.- References.- 2. Bulk-Wave Acousto-Optic Bragg Diffraction.- 2.1 A Simple Experiment.- 2.2 Historical Perspective.- 2.3 Heuristic Picture.- 2.4 Parametric Excitation and Bragg Diffraction.- 2.5 A Quantum-Mechanical Point-of-View.- 2.6 Wave Theory.- 2.7 A Sample Calculation.- 2.8 The Reflection Case.- 2.9 Birefringent Bragg Diffraction.- 2.10 Acousto-Optic Materials.- 2.11 Conclusion.- References.- 3. Optical Waveguides — Theory and Technology.- 3.1 Background.- 3.2 Wave Equations and Wave Vectors.- 3.3 The Zigzag-Wave Model.- 3.4 The Potential-Well Model.- 3.5 Mode Equations of a Slab Waveguide.- 3.6 Mode Equations of a Channel Waveguide.- 3.7 Effective-Index Method.- 3.8 Diffused Waveguides and the WKB Method.- 3.9 Waveguide Materials.- 3.9.1 Glass.- 3.9.2 Semiconductor.- 3.9.3 Lithium Niobate.- 3.9.4 Channel Waveguides.- 3.9.5 Ridge and Metal-Clad Channel Waveguides.- 3.9.6 Coupling to a Dielectric Waveguide.- 3.9.7 The Prism.- 3.9.8 Fiber-Waveguide Coupling.- References.- 4. Excitation of Surface-Acoustic Waves by Use of Interdigital Electrode Transducers.- 4.1 Fundamentals of Transducer Operation.- 4.1.1 Equivalent Circuit Model.- 4.1.2 Transducer Admittance and Conversion Efficiency.- 4.1.3 An Important Example.- 4.2 Design of Transducer and Coupling Networks for Broad-Band Operations.- 4.2.1 The Transducer-Circuit Sub-System.- 4.2.2 Broad-Band Acoustic Design.- 4.2.3 Broad-Band Electric Circuit Design.- 4.2.4 Parasitic and Second-Order Effects.- 4.3 Summary.- References.- 5. Wideband Acousto-Optic Bragg Diffraction in LiNbO3 Waveguide and Applications.- 5.1 Guided-Wave Acousto-Optic Bragg Interactions in Planar Waveguides.- 5.1.1 Basic Planar Acousto-Optic Bragg Interaction Configuration and Mechanisms.- 5.1.2 Coupled-Mode Analysis on Acousto-Optic Bragg Diffraction from a Single-Surface Acoustic Wave.- 5.1.3 Diffraction Efficiency and Frequency Response.- 5.1.4 Three Potential Acousto-Optic Substrate Materials.- a) LiNbO3 Substrate.- b) GaAs Substrate.- c) SiO2, AS2S3 or SiO2-Si Substrates.- 5.2 Key Performance Parameters of Basic Planar Acousto-Optic Bragg Modulators and Deflectors.- 5.2.1 Bandwidth.- 5.2.2 Time-Bandwidth Product.- 5.2.3 Acoustic and RF Drive Powers.- 5.2.4 Nonlinearity and Dynamic Range.- 5.3 Guided-Wave Acousto-Optic Bragg Diffraction from Multiple Surface Acoustic Waves.- 5.3.1 Acousto-Optic Bragg Diffraction from Two Tilted SAWs.- 5.3.2 Acousto-Optic Bragg Diffraction from N-SAWs.- 5.3.3 Two Specific Wide-Band Configurations.- a) Tilted-SAWs Configuration.- b) Phased-SAWs Configuration.- 5.4 Realization of Wide-Band Planar Acousto-Optic Bragg Modulators and Deflectors.- 5.4.1 Principle and Design Procedure of Wide-Band Device Configurations.- a) Isotropic Diffraction with Multiple Tilted Transducers of Staggered Center Frequency.- b) Isotropic Diffraction with Phased-Array Transducers.- c) Isotropic Diffraction with Multiple Tilted.- Phased-Array Transducers.- d) Isotropic Diffraction with a Single Tilted-Finger, Chirp Transducer or an Array of Such Transducers.- e) Optimized Anisotropic Diffraction with Multiple Transducers of Staggered Center Frequency or a Parallel-Finger Chirp Transducer.- 5.4.2 Design, Fabrication, Testing, and Measured Device Performance.- a) Isotropic Device with Multiple Tilted Transducers of Staggered Center Frequency.- b) Isotropic Device with Multiple, Tilted Transducers of Improved Geometry.- c) Isotropic Device with Phased-Array Transducers.- d) Isotropic Device with a Tilted-Finger, Chirp Transducer.- e) Optimized Anisotropic Device with a Single Transducer of Large Aperture.- 5.4.3 Relative Merits of Single Transducer Versus Multiple Transducers.- 5.5 Applications in Optical Communications, Signal Processing, and Computing.- 5.5.1 Optical Communications.- a) Digital Deflection and Switching.- b) Analog Deflection and Switching.- c) Electronically Tunable Optical Wavelength Filtering.- d) Wide-Band Optical Frequency Shifting.- 5.5.2 Optical Signal Processing.- a) Spectral Anlysis of Very Wide-Band RF Signals.- b) Convolution of Wide-Band RF Signals.- c) Compression of RF Chirp Pulse.- d) Correlation of Wide-Band RF Signals.- 5.5.3 Optical Computing.- 5.6 Summary.- References.- 6. Guided-Wave Acousto-Optic Interaction in a ZnO Thin Film on a Nonpiezoelectric Substrate.- 6.1 Fabrication of ZnO Thin Film.- 6.1.1 DC Sputtering.- 6.1.2 RF Sputtering.- 6.1.3 Chemical Vapor Deposition.- 6.1.4 Some Other Methods.- 6.1.5 Progress in ZnO Technology.- 6.2 The ZnO Thin-Film Waveguide.- 6.2.1 Fused Quartz Substrate.- 6.2.2 Sapphire Substrate.- 6.2.3 Si Substrate.- 6.3 Excitation of SAW by ZnO Thin Films.- 6.4 Photoelastic Effect in ZnO.- 6.5 Acousto-Optic Interaction in ZnO Thin Film.- 6.5.1 Diffraction Efficiency.- 6.5.2 Bragg Condition.- 6.5.3 Mode Conversion; TE ? TM, TMi ? TMj.- 6.6 Combined Structure of ZnO and Other Thin Films.- References.- 7. Spectrum Analysis with Integrated Optics.- 7.1 Acousto-Optic Spectrum Analysis.- 7.1.1 Frequency Resolution and Bandwidth.- 7.1.2 Dynamic Range.- 7.2 The Integrated Optical Spectrum Analyzer.- 7.2.1 IOSA Features.- 7.2.2 Size Constraints.- 7.2.3 Dynamic Range.- 7.2.4 Materials.- 7.3 Components.- 7.3.1 Laser and Laser/Waveguide Coupling.- a) Semiconductor Diode Laser Characteristics.- b) Butt-Coupling.- 7.3.2 Waveguides.- a) Silicon.- b) Lithium Niobate.- 7.3.3 Waveguide Lenses.- a) Generalized Waveguide Luneburg Lens.- b) Diffraction Lenses.- c) Geodesic Lenses.- 7.3.4 Wideband Waveguide Bragg Cells.- a) Frequency Dependence of the Diffraction Efficiency.- b) Wideband Transducer Configurations.- c) SAW Attenuation.- 7.3.5 Detection and Signal Processing.- a) Detector Array Architecture.- b) Post-Detection Processing.- c) Detector Sensitivity.- d) Dynamic Range.- e) Speed.- f) Photodetector Pitch.- g) Photodetector Coupling.- 7.4 IOSA Demonstrations.- 7.5 Related Applications.- 7.5.1 Acousto-Optic Correlation.- 7.5.2 Dual Bragg Cell Configurations.- 7.5.3 Other Processing Options.- 7.6 Summary.- References.- 8. Integrated Acousto-Optic Device Modules and Applications.- 8.1 RF Spectrum Analyzer Modules in Nonpiezoelectric Substrates.- 8.2 Acousto-Optic Time-Integrating Correlator Module Using Anisotropic Bragg Diffraction.- 8.3 Crossed-Channel Waveguide Acousto-Optic Modulator/ Deflector and Frequency-Shifter Modules.- 8.4 Channel-Planar Composite Waveguide Acousto-Optic Bragg Modulator Modules.- 8.5 Multichannel RF Correlator Modules Using Acousto-Optic and Electro-Optic Bragg Diffractions.- 8.6 Planar-Waveguide Acousto-Optic Frequency-Shifter Module.- 8.7 GaAs Acousto-Optic Bragg Cell and RF Spectrum Analyzer Modules.- 8.7.1 Geometry, Design and Fabrication of Acousto-Optic Bragg Cells in GaAs Waveguides....- 8.7.2 Measured Performances of AO Bragg Cells.- 8.7.3 GHz Acousto-Optic Bragg Cells.- 8.7.4 RF Spectrum Analyzer Module.- 8.8 Spherical Waveguide Acousto-Optic Bragg Modulator/ Deflector and Frequency-Shifter Modules.- 8.8.1 Optical Guiding and Propagation in a Spherical Waveguide and Acousto-Optic Interaction Configuration.- 8.8.2 Acousto-Optic Diffraction Experiments.- 8.8.3 Applications to Communications and RF Signal Processing.- 8.8.4 Spherical Waveguide Acousto-Optic Frequency Shifter Module.- 8.8.5 Summary.- 8.9 Conclusion.- References.

O autorze

Guided-Wave Acoustooptics reviews Bragg interactions between guided optical waves and acoustic waves, both in terms of basic theory and in the substrates LiNbO3, ZnO/SiO2 and GaAs, as well as the sideband modulators and deflectors that can be manufactured with this technology. Further applications described include light beam modulation and deflection, multiport switching in communications and spectral analysis, correlation and convolution in RF signal processing.