3. Materials, Fabrication and Characterization Methods
3.1 Wafer Bonding
3.1.1 Bonding with Intermediate Layer
3.1.2 Bonding without Intermediate Layer
3.1.3 Benzocyclobutene (BCB) Wafer Bonding
3.2 Dry Etching
3.3 Si based Materials
3.3.1 Ring Resonators based on Si–SiO2
3.3.2 Ring Resonators based on Ta2O5–SiO2
3.3.3 Ring Resonators based on SiN, SiON and Si3N4
3.3.4 Ring Resonators based on SiO2-GeO2
3.4 III-V Materials
3.4.1 The Quaternary Semiconductor Compound GaInAsP
3.4.2 The Semiconductor Compound AlGaAs
3.4.3 Lateral Coupling in GaInAsP/InP
3.4.4 Vertical Coupling in GaInAsP/InP
3.4.5 Lateral Coupling in AlGaAs/GaAs
3.4.6 Vertical Coupling in AlGaAs/GaAs
3.4.7 Implementation of Gain in Ring Resonators
3.5 Polymers
3.5.1 Conventional Fabrication Techniques
3.5.2 Replication and Nanoimprinting
3.5.3 Novel Polymer Devices
3.6 Temperature Insensitivity
3.7 Polarization Independence
3.8 Characterization Methods
3.8.1 Conventional Characterization
3.8.2 Optical Low Coherence Reflectometry (OLCR)
3.8.3 Evanescent Field Measurement Methods
3.9 Lithium niobate and hydrid solutions
3.9.1 Ring Resonators based on Lithium niobate
3.9.2 Ring Resonators based on Lithium niobate on Insulators ( LNOI)
3.9.3 Ring Resonators based on Lithium niobate in hybrid configurations with nitrides
4. Building Blocks of Ring Resonator Devices
4.1 Couplers
4.1.1 Directional Couplers
4.1.2 Multimode Interference Couplers
4.1.3 Y-Couplers
4.2 Bends
4.3 Spot Size Converters for Light In- and Outcoupling
4.4 Gratings for Light In- and Outcoupling
5. Devices & Applications
5.1 Filters
5.1.1 Passive Devices
5.1.2 Devices with gain section
5.2 Tunability Methods
5.2.1 Wavelength Tuning
5.2.2 Center Wavelength Trimming
5.2.3 Tunable Couplers in Ring Resonators
5.3 Dispersion Compensators
5.4 Mach-Zehnder combined with Ring Resonator
5.5 Modulators
5.6 Lasers
5.6.1 All Active Lasers
5.6.2 Devices with gain section
5.6.3 Passive Ring Resonator Coupled Lasers
5.7 Wavelength Converters
5.8 Optical Signal Processing
5.8.1 Logic Gates
5.8.2 Switching
5.8.3 Telecom Operations
6. Sensors
6.1 Microfluidics
6.2 Optofluidics
6.3 Biosensors
7. Whispering Gallery Mode Devices
7.1 Whispering Gallery Modes (WGM)
7.2 WGM Filters
7.3 WGM Lasers
7. Outlook
References
Index
D. G. Rabus is an internationally recognized photonics & sensor expert with an extensive track record of accomplishments in bridging academia and industry by way of numerous patents, path leading publications and books. Dr. Rabus holds a lecturer position at Reutlingen University, Germany, and is owner of RABUS.TECH, a technology consulting company enabling productization of key enabling technologies.
C. Sada is Professor in Experimental Physics of Condensed Matter at the University of Padova, Italy, with more than 250 internationally peer-reviewed publications. Her research focus is on integrated optics, opto-microfluidics and sensing by combining the material doping, growth and characterization of nano- to micro-scale properties.
This book describes the current state of the art in integrated ring resonators, covering more than two decades in the development of this exciting device. It discusses in depth one of the most fascinating and versatile integrated optical filters, providing readers with a panoramic view spanning from design and simulation to implementation in various material systems. Written by authors with extensive experience in both academia and industry, this second edition offers a much-needed, major update as interest in integrated ring resonators undergoes a global revival. The new edition includes a comprehensive technological update, and a timely discussion of recent advances in new application areas, such as optofluidics and microfluidics, telecom operations and biosensors. This aptly named compendium is the ideal guide for researchers and engineers looking to review the field as a whole while exploring several of its possible and exciting future trajectories.