PEER Project Descriptions: Summer 2002
1.
Coherent
Beam Combining
Prof. P-T Ho and Prof.
L. Yan (UMBC)
We propose to develop a technique of coherent beam combining based on spatial mixing of diffracted beams from multiple laser modules and mutual injection locking of them through feed back in a compound resonator. Proof of principle numerical study and experimental demonstration in a test bed will be carried out. Implementation of the technique to planar waveguide lasers, fiber-bundled lasers, and other laser systems will be explored.
2.
High
Temperature Dielectrics for Wide Bandgap Power Devices
Prof.
R. D. Vispute (Physics, UMCP)
Our current research activities under the PEER are focused on wide band gap semiconductors (particularly SiC) and related materials, processing, and devices to achieve ARL's goals on the Future Combat System of Systems (FCSS) that requires devices such as power switches and motor drive electronics to operate for 10,000 hours at junction temperatures of 300°C and above.
3.
Development
of P-Type SiC: Advanced Materials Processing and Characterization for
the Fabrication of Power Devices
Prof. T. Venkatesan
and R. P. Sharma
The recent focus on Future Combat Systems (FCS) has defined the role of the wide bandgap semiconductor, SiC for the fabrication of high-temperature and high-power electronics. Exploiting this material and novel process technologies, the Army is interested in developing a variety of electronic devices (MISFETS, GTO thyristors, diodes etc.) operating at high temperatures with high power. In the new PEER program we are proposing to continue our efforts to develop critical technologies and processes to deliver smooth and device quality, locally doped p-type SiC for the fabrication of high temperature and high-power devices such as the thyristor that are necessary for power electronics in future combat systems.
4.
Compact
Free-Electron Laser Research
Prof. P. O'Shea
The long-term goal of this
research is to develop improved and alternative methods of electron beam
modulation for compact, high-power free-electron lasers (FELs) and related
microwave sources.
Vacuum electronic sources of coherent radiation, including FEL operate
on the basic principle that a coherently microbunched or modulated electron
beam will radiate coherently when exposed to an appropriate radiating
mechanism, such as an FEL wiggler, a cavity, or a transition radiation
screen to name but a few. In a traditional wiggler based FEL, the bunching
and radiative mechanisms are both intertwined in the magnetic wiggler,
where the beam is first modulated, and later radiates. We are now considering
what we refer to as a "generalized" FEL, where the bunching
and radiative mechanisms are quite separate. This can lead to much more
flexible devices that can be adapted to suit many different requirements,
and may lead to devices where the wiggler itself can be replaced by an
alternative, more compact, radiator. The concept we are proposing here
may be applied over a very broad range of frequencies - from the microwave
to the optical, and is applicable high-power microwave sources as well
as FELs.
For further information on FELs see: http://www.ireap.umd.edu/FEL/
5.
Development
of MEMS-based Microphone and Speaker for Biomedical Applications
Prof. R. Ghodssi
Micro-Electro-Mechanical Systems (MEMS) are sensors and actuators constructed using microlithography-based manufacturing processes. MEMS technology is currently employed in a wide range of devices, including microaccelerometers for crash detection in vehicles, pressure sensors for implantable medical devices, miniature mirror arrays for projection displays, and chemical assay systems. The benefits of MEMS devices include small size, low power consumption, ease of integration into arrays, potential for monolithic integration with electronics, and low cost in high volume. This project involves the development of a MEMS-based microphone and speaker for biomedical application. The MEMS components are integrated modules of a Microsystem on a Chip that also includes optoelectronics components and VLSI circuit. In this project the tasks are divided into three areas of design, fabrication and testing of microstructures and microdevices. The preliminary design requires the use of standard software such as Matlab and MatCAD as well as state-of-the-art simulation software, MEMCAD. The MEMS Sensors and Actuators Lab (MSAL) in the Department of Electrical and Computer Engineering at the University of Maryland and the new cleanroom facility at the Army Research Lab (ARL) are used for the development of the new process technologies and fabrication of these devices. It is expected that the team members would interact closely with both graduate students and senior researchers in all three areas. The final goal is to examine and characterize the fabricated MEMS device and evaluate its performance based on required design criteria.