Advances in Terahertz Source Technologies

✍ Scribed by Gun-Sik Park, Masahiko Tani, Jae-Sung Rieh, Sang Yoon Park

• Publisher: Jenny Stanford Publishing
• Year: 2024
• Tongue: English
• Leaves: 773
• Edition: 1
• Category: Library

✦ Synopsis

During the past several decades, tremendous progress has been made in terahertz (THz) science and technology. There is a continuing need to have terahertz waves ready for practical applications. Terahertz photonic and electronic devices are being readied to be employed in application systems such as communication links, satellite communications, radar, surveillance, hard/soft material heating, biomedical treatment, and biomedical diagnostics. This book focuses on the advances in terahertz source technologies both from photonics and electronics (solid-state and vacuum-state) points of view. Written in a noncomplicated language, the book will be useful for a broad spectrum of readers, including advanced undergraduate- and graduate-level students in electronics and photonics, researchers in various disciplines in physics, chemistry, biology, astronomy, and electrical engineering, system engineers in various industrial sectors, general readers, and those who are interested in the interaction between electromagnetic waves and matters and in the effects of electromagnetic waves on matters.

✦ Table of Contents

Cover
Half Title
Title Page
Copyright Page
Table of Contents
Preface
Part I: THz Photonic Sources
Chapter 1: THz Optical Parametric Generators and Oscillators
1.1: Injection-Seeded THz-Wave Parametric Generation Pumped by Subnanosecond Near-Infrared Pulses
1.2: Highly Efficient THz-Wave Parametric Wavelength Conversion between Near-Infrared Light and THz Waves
1.3: Multi-Wavelength THz Parametric Generator
1.4: Rapidly Wavelength-Switchable THz Parametric Generator
1.5: Backward THz-Wave Parametric Oscillation
Chapter 2: Terahertz Wave Emission with Photoconductive Antennas
2.1: Operation Principles of Photoconductive Antennas
2.2: Design Considerations of Photoconductive Antennas
2.2.1: Photoconductive Material
2.2.2: Antenna Structure
2.2.3: Pump Laser
2.2.4: Sub-bandgap excitation of LT-GaAs-based Photoconductive antennas
2.3: Plasmonics-Enhanced Photoconductive Antennas
2.3.1: PCAs Based on Plasmonic Light Concentrators
2.3.2: PCAs Based on Plasmonic Contact Electrodes
2.3.3: PCAs Based on Plasmonic Nanoantenna Arrays
2.3.4: PCAs Based on Plasmonic Nanocavities
2.4: Conclusion and Outlook
Chapter 3: Optical Rectification–Based Sources
3.1: Phase Matching, Velocity Matching, Tilted Pulse Front
3.2: Semiconductor-Based Sources
3.2.1: Contact Grating
3.2.2: Multiphoton Absorption
3.3: Organic Crystal-Based Sources
3.4: Lithium Niobate–Based Sources
3.4.1: Limitations of TPF
3.4.2: New Designs
3.5: Dispersion of Refractive Index, Absorption and Nonlinear Coefficient
3.6: Models for THz Generation
3.7: Summary
Chapter 4: Method of Terahertz Liquid Photonics
4.1: Background
4.2: Liquid for THz Source
4.3: THz Wave Emission under Single-Color Optical Excitation in a Thin Water Film
4.4: THz Wave Emission under the Excitation of Asymmetric Optical Fields
4.5: THz Emission from Waterlines
4.6: Summary of Results of THz Wave Generation from Liquid Water
4.6.1: Key Observations
4.6.2: Other Confirmations
4.7: THz Wave Generation from Liquid Metal
4.8: THz Wave Generation from Liquids with Nanoparticles
4.9: THz Wave Emission from Liquid Nitrogen
4.10: Density Singularity of Water at 4°C
4.11: Molecular Orientation and Alignment
4.12: Magnetic Fluids
4.13: Future Perspective
4.14: Summary
Chapter 5: Photomixing THz Sources
5.1: Generation of CW THz Radiation Using Photomixing
5.1.1: Devices for Photomixing THz Sources and THz Radiation Powers
5.1.2: Generation of THz Radiation Using Superposed Two Single-Mode Laser Beams (Two-Beam Photomixing)
5.1.3: Generation of THz Radiation by Photomixing Using a Dual-Mode Laser
5.1.4: Generation of THz Radiation by Photomixing Using a Multimode Laser
5.2: Photomixing THz Sources Combined with Coherent Detection
5.2.1: Coherent Detection System Using Superposed Two Single-Mode Laser Beams
5.2.2: Cross-Correlation Spectroscopic System (CCS)
5.3: Stable CW THz Wave Generation and Detection Using Laser Chaos
5.3.1: Laser Chaos
5.3.1.1: Time evolution of variables
5.3.1.2: Classification of lasers
5.3.1.3: Effects of delayed feedback
5.3.2: Application of Laser Chaos to Generation of THz Radiations
5.3.2.1: Merits of LDs as an irradiation source for THz radiation generation
5.3.2.2: Optical spectra of laser chaos
5.3.2.3: Generated THz waves
5.3.2.4: Simple stabilization mechanism
5.3.2.5: Stability of optical beats in laser chaos
5.3.3: Further Challenges
Chapter 6: Spintronic THz Emitters
6.1: Introduction
6.2: Spin-to-Charge Conversion Mechanism Responsible for THz Radiation
6.3: Experimental Detection of THz Emission
6.4: Strategies to Engineer Intensity and Bandwidth of THz Signal
6.4.1: Material Dependence
6.4.2: Thickness Dependence
6.4.3: Wavelength Dependence
6.4.4: Interface Dependence
6.4.5: Stack Geometry Dependence
6.5: Future Perspectives of THz STEs
6.6: Conclusion
Chapter 7: Terahertz Frequency Comb
7.1: Introduction
7.2: Coherent Link of Frequency Using Frequency Comb
7.3: THz-Comb-Referenced Spectrum Analyzer
7.4: Optical-Comb-Referenced Frequency Synthesizer
7.5: Dual-THz-Comb Spectroscopy
7.6: Conclusions and Future Trends
Part II: THz Solid-State Electronic Sources
Chapter 8: High-Efficiency THz Oscillators
8.1: Introduction
8.1.1: Fundamental Oscillators
8.1.2: Harmonic Oscillators
8.2: Challenges
8.3: Design and Optimization Flow
8.4: Design Example
8.4.1: Optimization Target
8.4.2: Core Transistor Optimization
8.4.3: Transformer-Based Impedance Optimization
8.5: Conclusion
Chapter 9: Resonant Tunneling Diode (RTD) THz Sources
9.1: Introduction
9.2: Characteristics of RTD Oscillators
9.2.1: Structure and Oscillation Principle
9.2.2: Toward High-Frequency and High-Power Oscillation
9.2.3: Functionality
9.3: Applications of RTD Oscillators
9.3.1: Wireless Communication
9.3.2: Imaging and Radar
9.3.3: Analytics
9.4: Summary
Chapter 10: Plasmon-Based THz Oscillators
10.1: Introduction
10.2: Theory
10.2.1: Hydrodynamics of 2D Plasmons
10.2.2: Dyakonov–Shur Doppler-Shift-Type Instability
10.2.3: Ryzhii–Satou–Shur Electron-Transit-Type Instability
10.2.4: Cherenkov Plasmonic-Boom-Type Instability
10.2.5: Coupling between Plasmons and Photons
10.3: Experiments
10.3.1: AlGaN/GaN Single-Gate HEMT
10.3.2: InGaAs/InAlAs/InP Dual-Grating-Gate HEMT
10.3.3: Graphene-Channel Dual-Grating-Gate FET
10.4: Future Subjects and Prospects
10.5: Conclusion
Chapter 11: Beamforming THz Transmitters
11.1: Introduction
11.2: THz Phase Shifters
11.2.1: Reflective-Type Phase Shifters (RTPS)
11.2.2: Switched-Type Phase Shifters (STPS)
11.2.3: Vector-Sum Phase Shifters (VSPS)
11.3: Integrated Beamforming THz Transmitters
11.3.1: 280 GHz CMOS Beamforming Array on Distributed Active Radiators
11.3.2: 320 GHz BiCMOS Beamforming Transmitter
11.3.3: 370–410 GHz CMOS Beamforming Transmitter
Chapter 12: Solid-State THz Power Amplifiers
12.1: Introduction
12.2: THz Power Amplifier Fundamentals
12.2.1: Unit Cell Design
12.2.2: Power Combining Techniques
12.2.3: Power Supply Oscillations and Heat Effect
12.2.4: Technology Considerations
12.3: Design Examples
12.3.1: 140 GHz Power Amplifier
12.3.1.1: Unit cell design
12.3.1.2: Combiner design
12.3.1.3: Measurement results
12.3.2: 210 GHz Power Amplifier
12.3.3: 270 GHz Power Amplifier
12.3.4: 600 GHz Power Amplifier
12.3.4.1: Unit gain stage
12.3.4.2: Differential gain block
12.3.4.3: Measurement results
Chapter 13: Terahertz Silicon On-Chip Antenna
13.1: Introduction
13.2: Si IC Technologies for on-Chip Antenna
13.3: Topside Radiating Antenna with Frontside Ground
13.3.1: Antenna Structure and Design Considerations
13.3.2: Design Examples
13.3.2.1: On-chip patch antenna
13.3.2.2: Slot antenna
13.3.2.3: Antenna with AMC
13.4: Topside Radiating Antenna with Backside Ground
13.4.1: Antenna Structure and Design Considerations
13.4.2: Design Examples
13.4.2.1: Slot-ring antenna
13.4.2.2: Dipole antenna
13.4.2.3: Patch antenna with DGS
13.4.2.4: Comb-shaped dipole with chip-integrated dielectric resonator
13.5: Backside Radiating on-Chip Antenna
13.5.1: Antenna Structure and Design Considerations
13.5.2: Design Examples
13.5.2.1: Backside radiating antenna with a lens
13.5.2.2: Backside radiating antenna without lens
13.6: Design Rules Related to Antenna Design
Chapter 14: Package Technologies for THz Devices
14.1: Introduction
14.2: Issues in Package at THz Frequencies
14.2.1: Packaging Materials
14.2.2: Interconnections
14.2.3: Signal Interfaces
14.3: Metallic Waveguide Packages
14.4: LTCC Packages at THz Frequencies
14.5: Concept of Quasi-Optical THz Package
Chapter 15: Semiconductor Technologies for THz Applications
15.1: Si CMOS Technology
15.1.1: Device Operation
15.1.2: Structural Variations
15.1.2.1: SOI MOSFET
15.1.2.2: FinFET and GAA FET
15.1.3: Performance Trend
15.2: SiGe HBT Technology
15.2.1: Device Operation
15.2.2: Performance Trend
15.3: III–V HEMT Technology
15.3.1: Device Operation
15.3.2: Performance Trend
15.4: III–V HBT Technology
15.4.1: Device Operation
15.4.2: Performance Trend
Part III: THz Vacuum Electronic Sources
Chapter 16: Development and Applications of THz Gyrotrons
16.1: Introduction
16.2: Development of THz Gyrotrons
16.3: THz Gyrotrons: New Concepts, Challenges, and Trends in Their Development
16.4: Some of the Most Prominent Applications of THz Gyrotrons
16.4.1: Controlled Thermonuclear Fusion
16.4.2: Materials Treatment
16.4.3: Advanced Spectroscopic Techniques
16.4.3.1: DNP-NMR spectroscopy
16.4.3.2: ESR spectroscopy
16.4.3.3: XDMR spectroscopy
16.4.3.4: Measuring the energy levels of positronium
16.4.3.5: Radioacoustic spectroscopy using gyrotron radiation
16.4.4: Plasma Physics and Localized Gas Discharges
16.4.5: Electron Cyclotron Resonance Ion Sources
16.4.6: Applications in Bioscience and Material Science Areas
16.5: Conclusions and Outlook
Chapter 17: Extended-Interaction Klystrons
17.1: EIK Cavity
17.2: Beam-Wave Interaction in EIK
17.3: Gain
17.4: RF Power
17.5: Sheet-Beam EIKs
17.6: THz EIKs
17.7: Conclusions
Chapter 18: THz Oscillators Based on Cherenkov, Smith–Purcell and Hybrid Radiation Effects
18.1: Introduction
18.2: Theory of Cherenkov and Smith–Purcell/Diffraction Radiation Effects
18.3: Principles of THz BWO Design and Challenges for Efficient Generation in the THz Range. The Clinotron Effect
18.3.1: Principle of the Clinotron
18.4: Mode Transformation in Oversized Circuits in the THz Range
18.4.1: Simulation and Experimental Results
18.5: Principles for Design of the THz Diffraction Radiation Oscillator
18.6: Excitation of THz Self-Oscillations in Resonant Systems Supporting Hybrid Bulk-Surface Modes: Cavity with Bieriodic Grating and Electromagnetic Mode Interaction
18.6.1: Feedback by the Backward Radiating Harmonic
18.6.2: Radiation Angle Is Normal to the Grating
18.6.3: Regime of Grazing Radiation Angle
18.6.4: Experimental Results
18.7: Conclusion
Chapter 19: Folded Waveguide Traveling Wave Tube
19.1: Introduction
19.2: Theory and Algorithm
19.2.1: High-Frequency Characteristics
19.2.2: Theory of Beam-Wave Interaction
19.3: Improvement of High-Frequency Structure
19.3.1: Ridge/Groove-Loaded FW SWS
19.3.2: Metamaterial Structure Loaded FW SWS
19.3.3: Nonuniform-Unit FW SWS
19.3.4: Resonant Cavity Loaded FW-TWT
19.3.5: High-Order Harmonic Amplifier FWSWS
19.3.6: Multibeam/Sheet-Beam FW SWS
19.4: Electron Optical System
19.5: Fabrication Technology
19.5.1: EDM
19.5.2: CNC
19.5.3: DRIE
19.5.4: LIGA
19.5.5: Other Technologies
19.6: Performance of FW-TWT
19.7: Conclusion
Chapter 20: Vacuum Nanoelectronics and Electron Emission Physics
20.1: Background
20.2: Emission Equations
20.2.1: Thermal Emission
20.2.2: Photoemission
20.2.3: Tunneling Emission
20.2.4: Gamow and Shape Factors
20.2.5: Field Emission
20.2.6: Beyond the Simple Models
20.3: Heating Effects in Field Emission
20.3.1: Simple Model
20.3.2: Heating of Wires and Nanotubes
20.4: Time Factors
20.4.1: Tunneling Time
20.4.2: Transit Time
20.5: Quadratic Barriers
20.6: Space Charge
20.6.1: Non-Planar Image Charge
20.6.2: Conical Emitters
20.6.3: Depletion Barrier
20.6.4: Shape Factors Including Image Charge
20.7: Concluding Remarks
Chapter 21: Terahertz Free-Electron Laser
21.1: Historical Introduction
21.2: Theory
21.2.1: The Basis
21.2.1.1: Considerations about efficiency
21.2.2: Waveguide Operation and Dispersion Relations
21.3: The Source Survey
21.3.1: Undulator Based FELs
21.3.1.1: The ENEA THz Compact-FEL
21.3.1.2: Coherent spontaneous emission and energy-phase correlation
21.3.2: Cerenkov, Smith–Purcell and Other Devices
21.4: Gimmicks: Novel Schemes
21.4.1: Tailoring THz Radiation Properties
21.4.2: Techniques to Optimize FEL Performance in the THz Range
21.4.2.1: Wide-band emission
21.4.2.2: Buncher-emitter scheme
Chapter 22: Cathode Technologies for Terahertz Source
22.1: Introduction
22.2: Emission Physics of Cathode
22.2.1: Fermi Level
22.2.2: Vacuum Level
22.2.3: Work Function
22.3: Classifications of Emission Mechanism
22.3.1: Thermionic Emission
22.3.2: Evolution of Thermionic Cathode
22.3.2.1: Modern dispenser cathode
22.4: Thermionic Cathode for Terahertz Devices
22.4.1: CPD Cathode
22.4.2: Nanoparticle-Based Cathode
22.5: Field Emitter Cathode for Terahertz Devices
22.5.1: Field Emission Theory
22.5.1.1: Calculation of supply function and transmission coefficient
22.6: Conclusions and Future Prospects
Chapter 23: Microfabrication Technologies
23.1: Introduction
23.1.1: Purpose/Objectives
23.1.2: The State of Microfabrication Techniques
23.1.3: Scope of Chapter, Scales
23.2: Microfabrication Materials
23.2.1: Copper
23.2.1.1: Electronic grade oxygen-free copper
23.2.1.2: Cupronickel
23.2.1.3: Glidcop ®
23.2.1.4: Elkonite ®
23.2.2: Silver
23.2.3: Aluminum
23.2.4: Other Alloys
23.2.5: Lossy and Dielectric Materials
23.3: Machines and Techniques
23.3.1: Subtractive Methods
23.3.2: Additive Methods
23.3.2.1: Direct AM
23.3.2.2: Indirect AM
23.3.2.3: Inverse AM
23.3.3: Hybrid Manufacturing
23.3.4: Multi-Material Manufacturing
23.3.4.1: Micro-CNC
23.3.4.2: Electron beam AM
23.3.4.3: Laser powder bed fusion (L-PBF)
23.3.4.4: Binder jetting
23.3.4.5: Electrical discharge machining
23.3.4.6: Laser ablative machining (subtractive)
23.3.4.7: Lithography
23.3.4.8: Deep reactive ion etching
23.3.4.9: 3D photopolymer printing
23.3.5: Surface Treatments
23.4: Joining/Brazing
23.4.1: Brazing
23.4.2: Diffusion Bonding
23.4.3: Transient Liquid Phase Bonding
23.4.4: Laser welding
23.5: Recommendations and Application to THz Devices
23.6: Discussion, Conclusion, and Outlook
Index