University of California
at Santa Barbara
Computer and Electrical Engineering Department
LIGHT DIFFRACTION Diffraction phenomena can be explained by the wave theory of light. It was assumed for a long time that light travels In a straight line; however It was found that It bends around obstacles. The light streaks that we perceive when we look at a strong and concentrated light source with half-shut eyes is a diffraction phenomenon. In this picture we see the diffraction pattern of laser light by a hexagonal array of dots with 0.08 mm spacing.
Students in the Ultrasonics and Laser Laboratory work on a device called an Opto-Acoustic Transducer (OAT). This device transforms an optical pattern to a corresponding acoustic pattern, and it will be used in an acoustical imaging system which produces pictures using ultrasound as the illumination energy.
The task in the lab is to improve the OAT device so that real-time, good-quality acoustic images will be possible in future acoustic imaging systems. A graduate student makes tests in the Microwave Laboratory on a new form of dielectric waveguide filter circuit which has potential applications for millimeter-wave and optical integrated circuits.
CURRENT RESEARCH PROJECTS IN MICROWAVE, OPTICS, AND ACOUSTICS
Dielectric Waveguide Filter and
Matching-Structure Design
High Sensitivity Diagnostics Imaging System
Coherent Doppler Tomography
Acoustic Holograms of Moving Objects in Random Media
Scanning Tomographic Acoustic Microscope
Acoustical Vibrational Analysis Speckle Reduction by Object Vibration
Signals and Systems
Signals and Systems research¬ers are concerned both with the development of new theories, devices and techniques for signal processing and analysis and system design, and with the practical applications of these to such diverse disciplines as control, communications, and instrumentation. Theoretical studies include the development of decision and control techniques for decentralized and large-scale systems, especially those in which uncertainty plays an essential role. New designs for analog and digital filters, including computationally efficient implementation of digital filters and switched-capacitor filter design, are currently being studied, along with extended state-space models of discrete-time systems
for application to large-scale systems and problems. Digital coding of speech and images is being investigated for application to digital storage, processing, and transmission, as well as speech scrambling and encryption, and speech support for laryngectomies. Many of the signal processing studies
are now being oriented toward VLSI implementations to be carried out in conjunction with the Solid-State group. Sophisticated signal processing algorithms are being developed for high-resolution radar imaging, which is in
turn being used to develop deterministic scatterer models for radar target simulation. Also under current research is the processing
of biological data and the development of models for use in designing microprocessors and computer programs for medical use.
Microwaves, Optics, and Acoustics
The promise of new tools for medical diagnosis using acoustic imaging, and the implementation of optical and microwave integrated circuits is fueling research efforts in the area of Microwaves, Optics, and Acoustics. A pioneering effort is being made at UCSB to develop an acoustic imaging system--like a "sound X-ray"
for safe medical diagnosis of the soft tissues of the body, both at rest and in motion. The use of computer tomography to obtain images of microscopic test samples using a scanning laser acoustic camera (Scanning Tomographic Acoustic Microscope) is also being investigated. Research in Coherent Doppler Tomography (CDT) for microwave imaging, and optical processing of CDT images promises new systems in which superresolution of radar images with minimum hardware requirements can be achieved. Also under current research is the use of dielectric waveguide filter and coupler techniques for millimeter-wave and optical frequency integrated circuit applications.
Laboratory and Computational Facilities
The Department of Electrical and Computer Engineering maintains extensively equipped laboratories both for undergraduate learning and for graduate teaching and research. The Solid State Laboratory is among the best university solid-state laboratories in the nation. Specialized computing facilities, department computing facilities, and the UCSB Computer Center are also available for teaching and research.
University of California
