The International Workshop on "Intersubband Transitions in Quantum Wells:: Physics and Applications," was held at National Cheng Kung University, in Tainan, Taiwan, December 15-18, 1997. The objective of the Workshop is to facilitate the presentation and discussion of the recent results in theoretical, experimental, and applied aspects of intersubband transitions in quantum wells and dots. The program followed the tradition initiated at the 1991 conference in Cargese-France, the 1993 conference in Whistler, B. C. Canada, and the 1995 conference in Kibbutz Ginosar, Israel. Intersubband transitions in quantum wells and quantum dots have attracted considerable attention in recent years, mainly due to the promise of various applications in the mid- and far-infrared regions (2-30 J. lm). Over 40 invited and contributed papers were presented in this four-day workshop, with topics covered most aspects of the intersubband transition phenomena including: the basic intersubband transition processes, multiquantum well infrared photodetector (QWIP) physics, large format (640x480) GaAs QWIP (with 9. 0 J. lffi cutoff) focal plane arrays (FPAs) for IR imaging camera applications, infrared modulation, intersubband emission including mid- and long- wavelength quantum cascade (QC) lasers such as short (A. "" 3. 4 J. lm) and long (A. "" 11. 5 J. lm) wavelength room temperature QC lasers, quantum fountain intersubband laser at 15. 5 J. lm wavelength in GaAs/AIGaAs quantum well, harmonic generation and nonlinear effects, ultra-fast phenomena such as terahertz (THz) intersubband emission and detection. The book divides into five Chapters.

1 Intersubb and Emission and Lasers.- Short (? ? 3.4 ?m) and Long (? ? 11.5 ?m) Wavelength RoomTemperature Quantum Cascade Lasers.- Quantum Fountain Intersubband Laser at 15.5 ?m Wavelength in GaAs/AlGaAs Quantum Wells.- Quantum Cascade Electroluminescence in the GaAs/AlGaAs Material System.- Phase-Matched Second-Harmonic and Cascade Laser Mid-IR Sources.- Mid-Infrared Intersubband Emission and Lasing in Optically Pumped Coupled Quantum Well Structures.- Intersubband Electroluminescence from GaAs/AlGaAs Triple Barrier and Quantum Cascade Structures.- 2 Quantum Well Infrared Photodetec Tor Physics.- Quantum Well Infrared Photodetectors: Device Physics and Light Coupling.- QWIP Performance and Polarization Selection Rule.- Electric Field Distribution and Low Power Nonlinear Photoresponse of Quantum Well Infrared Photodetectors.- Intersubband Transitions of Normal Incidence N-Type Direct Bandgap Quantum Well Structures.- Calculation and Photoresponse Measurements of the Long-Wavelength IR Absorption in P-Type GaAs/AlGaAs Quantum Wells and Type-II InAs/InGaSb Superlattices.- Optical Response Induced By Intersubband Transitions in Quantum Wells: The Role of Multiple Reflections.- The Nature of Unintentional Deep Level Clusters Responsible for Persistent Photoconductivity Effect in GaAs/AlGaAs MQ Photodetectors.- Lateral Physical Effects in Quantum Well Infrared Photodetectors.- 3 Quantum Well and Quantum dot Infrared Detectors.- Strain-Layer Quantum Well Infrared Photodetectors.- Normal Incidence Two Color Voltage Tunable InGaAs Quantum Well Infrared Photodetectors.- Corrugated Quantum Well Infrared Photodetectors and Transistors.- Normal-incidence P-type Si/SiGe Mid-infrared Detector with Background Limited Performance up to 85 K.- Far-Infrared (?c ? 28.6 ?m)GaAs/AlGaAs Quantum Well Photodetectors.- Quantum Dots Infrared Photodetctors (QDIPs).- Intraband Absorption Spectroscopy of Self-Assembled Quantum Dots.- Spectral Dynamics of the Intersubband Absorption in Quantum Well Structures After Ultrafast IR Excitation.- Energy Relaxation of Electrons in GaAs/AlGaAs Quantum Wells and Superlattices.- Modulated Resonant Raman Spectroscopy Induced by Intersubband Optical Excitation of the Quantum Well Bound and Continuum States.- THz Intersubband Lasers Using the Inverted Mass Scheme.- THz Time-Domain Spectroscopy of an Intersubband Plasmons.- Electrically Excited Terahertz Emission from Parabolic Quantum Wells.- Momentum Space Redistribution Time of Resonantly Photoexcited Excitons in GaAs/AlGaAs Superlattices.- 5 Qwip Focal Plane Arrays (FPAs) for IR Imaging.- 9 Micron Cutoff 640x486 GaAs/AlxGa1-xAs Quantum Well Infrared Photodetector Snap-Shot Camera.- System Considerations in the Design of QWIP-Based Thermal Imager.- Electrical and Optical Properties of 8 - 12 ?m GaAs/AlGaAs Quantum Well Infrared Photodetectors in 256 x 256 Focal Plane Arrays.