Ultrafast All-Optical Signal Processing Devices

Dr Hiroshi Ishikawa, Tsukuba, JapanDr Ishikawa is the Director of the Ultrafast Photonic Devices Laboratory in National Institute of Advanced Industrial Science and Technology (AIST) in Japan. He worked for research and development of optical semiconductor devices in Fujitsu Labs Ltd from 1972 to 2001. In 2001 he moved to Femtosecond Technology Research Association Central Res. Lab. as a group leader of ultrafast all-optical switching devices. He is at AIST since 2004. He is a member of Japan Society of Applied Physics, The Physical Society of Japan, The Institute of Electronics, Information and Communication Engineers, and IEEE (Fellow).

• Contributors ixPreface xi1 Introduction 1Hiroshi Ishikawa1.1 Evolution of Optical Communication Systems and Device Technologies 11.2 Increasing Communication Traffic and Power Consumption 21.3 Future Networks and Technologies 41.3.1 Future Networks 41.3.2 Schemes for Huge Capacity Transmission 51.4 Ultrafast All-Optical Signal Processing Devices 61.4.1 Challenges 61.4.2 Basics of the Nonlinear Optical Process 71.5 Overview of the Devices and Their Concepts 111.6 Summary 13References 132 Light Sources 15Yoh Ogawa and Hitoshi Murai2.1 Requirement for Light Sources 152.1.1 Optical Short Pulse Source 162.1.2 Optical Time Division Multiplexer 192.2 Mode-locked Laser Diodes 202.2.1 Active Mode Locking 202.2.2 Passive Mode Locking 232.2.3 Hybrid Mode Locking 252.2.4 Optical Synchronous Mode Locking 272.2.5 Application for Clock Extraction 292.3 Electro-absorption Modulator Based Signal Source 302.3.1 Overview of Electro-absorption Modulator 302.3.2 Optical Short Pulse Generation Using EAM 332.3.3 Optical Time Division Multiplexer Based on EAMs 382.3.4 160-Gb/s Optical Signal Generation 412.3.5 Detection of a 160-Gb/s OTDM Signal 432.3.6 Transmission Issues 462.4 Summary 47References 473 Semiconductor Optical Amplifier Based Ultrafast Signal Processing Devices 53Hidemi Tsuchida and Shigeru Nakamura3.1 Introduction 533.2 Fundamentals of SOA 533.3 SOA as an Ultrafast Nonlinear Medium 563.4 Use of Ultrafast Response Component by Filtering 573.4.1 Theoretical Background 573.4.2 Signal Processing Using the Fast Response Component of SOA 603.5 Symmetric Mach–Zehnder (SMZ) All-Optical Gate 643.5.1 Fundamentals of the SMZ All-Optical Gate 643.5.2 Technology of Integrating Optical Circuits for an SMZ All-Optical Gate 673.5.3 Optical Demultiplexing 683.5.4 Wavelength Conversion and Signal Regeneration 733.6 Summary 83References 834 Uni-traveling-carrier Photodiode (UTC-PD) and PD-EAM Optical Gate Integrating a UTC-PD and a TravelingWave Electro-absorption Modulator 89Hiroshi Ito and Satoshi Kodama4.1 Introduction 894.2 Uni-traveling-carrier Photodiode (UTC-PD) 914.2.1 Operation 914.2.2 Fabrication and Characterization 964.2.3 Characteristics of the UTC-PD 984.2.4 Photo Receivers 1144.3 Concept of a New Opto-electronic Integrated Device 1174.3.1 Importance of High-output PDs 1174.3.2 Monolithic Digital OEIC 1184.3.3 Monolithic PD-EAM Optical Gate 1184.4 PD-EAM Optical Gate Integrating UTC-PD and TW-EAM 1194.4.1 Basic Structure 1194.4.2 Design 1204.4.3 Optical Gating Characteristics of PD-EAM 1234.4.4 Fabrication 1254.4.5 Gating Characteristics 1274.4.6 Applications for Ultrafast All-Optical Signal Processing 1314.4.7 Future Work 1434.5 Summary and Prospects 147References 1485 Intersub-band Transition All-Optical Gate Switches 155Nobuo Suzuki, Ryoichi Akimoto, Hiroshi Ishikawa and Hidemi Tsuchida5.1 Operation Principle 1555.1.1 Transition Wavelength 1565.1.2 Matrix Element 1575.1.3 Saturable Absorption 1575.1.4 Absorption Recovery Time 1585.1.5 Dephasing Time and Spectral Linewidth 1605.1.6 Gate Operation in Waveguide Structure 1625.2 GaN/AlN ISBT Gate 1645.2.1 Absorption Spectra 1655.2.2 Saturation of Absorption in Waveguides 1685.2.3 Ultrafast Optical Gate 1705.3 (CdS/ZnSe)/BeTe ISBT Gate 1725.3.1 Growth of CdS/ ZnSe/ BeTe QWs and ISBT Absorption Spectra 1735.3.2 Waveguide Structure for a CdS/ ZnSe/ BeTe Gate 1775.3.3 Characteristics of a CdS/ ZnSe/ BeTe Gate 1815.4 InGaAs/AlAs/AlAsSb ISBT Gate 1835.4.1 Device Structure and its Fabrication 1835.4.2 Saturation Characteristics and Time Response 1845.5 Cross-phase Modulation in an InGaAs/AlAs/AlAsSb-based ISBT Gate 1865.5.1 Cross-phase Modulation Effect and its Mechanisms 1875.5.2 Application to Wavelength Conversion 1925.6 Summary 195References 1966 Wavelength Conversion Devices 201Haruhiko Kuwatsuka6.1 Introduction 2016.2 Wavelength Conversion Schemes 2026.2.1 Optical Gate Switch Type 2026.2.2 Coherent Type Conversion 2046.3 Physics of Four-wave Mixing in LDs or SOAs 2056.3.1 Model 2056.3.2 Asymmetric χ(3) for Positive and Negative Detuning 2106.3.3 Symmetric χ(3) in Quantum Dot SOAs 2126.4 Wavelength Conversion of Short Pulses Using FWM in Semiconductor Devices 2146.4.1 Model 2146.4.2 The Effect of the Stop Band in DFB-LDs 2176.4.3 The Effect of the Depletion of Gain 2186.4.4 The Pulse Width Broadening in FWM Wavelength Conversion 2196.5 Experimental Results ofWavelength Conversion Using FWM in SOAs or LDs 2206.5.1 Wavelength Conversion of Short Pulses Using a DFB-LD 2206.5.2 Wavelength Conversion of 160-Gb/s OTDM Signal Using a Quantum Dot SOAs 2216.5.3 Format-free Wavelength Conversion 2226.5.4 Chromatic Dispersion Compensation of Optical Fibers Using FWM in DFB-LDs 2246.6 The Future View ofWavelength Conversion Using FWM 2256.7 Summary 226References 2267 Summary and Future Prospects 231Hiroshi Ishikawa7.1 Introduction 2317.2 Transmission Experiments 2317.2.1 FESTA Experiments 2317.2.2 Test Bed Field Experiment 2357.2.3 Recent Transmission Experiments above 160-Gb/s 2367.3 Requirements on Devices and Prospects 2387.3.1 Devices Described in this Book 2387.3.2 Necessity for New Functionality Devices and Technology 2407.4 Summary 241References 242Index 243