This grant provides support for developing enhancements to a stable, user-friendly high-power terahertz source, the Free-Electron Laser (FEL), at the University of California, Santa Barbara. Scientific disciplines that make use of terahertz radiation include astrophysics, earth science, biophysics, condensed matter physics, and chemistry. Emergent technological applications include imaging, biological and chemical agent detection, optical communications, remote sensing, and ultrafast electronics. The UCSB Free-Electron Lasers and newly renovated User's Lab stand out as unique facilities that enable measurements that can be done nowhere else. Current scientific activity is predominantly in the area of semiconductor physics. Activity related to semiconductors includes the development of new sources and detectors of Terahertz radiation, the study of new types of interactions between ultrastrong light and matter, Terahertz modulation of light beams for optical communications, and quantum information processing. In addition, there is a growing activity in biophysics. Collaborations bring visitors from Europe and Japan as well as other institutions in the U. S. The new enhancements will (1) modernize the control system to improve the stability and reproducibility of all the UCSB FELs to make them more user friendly for all operators, and to double the available frequency range to 10 terahertz; (2) stabilize the frequency to eliminate pulse-to-pulse frequency jitter, narrow the linewidth, and greatly reduce fluctuations in intensity within a pulse to enhance existing applications of the FELs and new applications, like electron spin resonance and high-resolution chemical spectroscopy; (3) build a FEL spectrometer to accurately display the operating frequency of the FEL's. Users will then have real-time feedback on FEL frequency.
The enhancement of the UCSB FELs will provide new capabilities for the development of science and technology at Terahertz frequencies. Terahertz science and technology at UCSB cuts across many disciplines, including semiconductor physics, optical communications, quantum information processing, and biophysics. The enhancements will increase productivity of users of the FELs and associated facilities, who include undergraduates, graduate students, post-doctoral researchers, and faculty at UCSB, and junior and senior visitors from other institutions in the U. S. and abroad. High-school students and teachers also participate in research associated with the UCSB FELs. There is recently increasing interest from private industry. The enhancements will be carried out in large part by undergraduates and graduate students affording them an exciting real-world research opportunity and valuable training.
