The purpose of Intersubband Transitions in Quantum Wells: Physics and Devices 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. This reference work is based on the International Workshop that was held at National Cheng Kung University in Tainan, Taiwan in December 15-18, 1997. 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 mum). Over 40 invited and contributed papers were presented in this four-day workshop, with topics covering most aspects of the intersubband transition phenomena including: the basic intersubband transition process, multiquantum well infrared photodetector (QWIP) physics, large format (640×480) GaAs QWIP (with 9.0 mum 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 (lambda = 3.4 mum) and long (lambda = 11.5 mum) wavelength room temperature QC lasers, quantum fountain intersubband laser at 15.5 mum wavelength in GaAs/AIGaAs quantum well, harmonic generation and nonlinear effects, ultra-fast phenomena such as terahertz (THz) intersubband emission and detection. Intersubband Transitions in Quantum Wells: Physics and Devices will be of interest to researchers from universities and industrial laboratories working on physics and devices of nanostructures, and researchers in the infrared (IR) community.