NASA SBIR 2004 Solicitation

FORM B - PROPOSAL SUMMARY


PROPOSAL NUMBER: 04 S2.01-9515
SUBTOPIC TITLE: Sensors and Detectors for Astrophysics
PROPOSAL TITLE: Metal Mesh Filters for Terahertz Receivers

SMALL BUSINESS CONCERN (Name, E-mail, Mail Address, City/State/Zip, Phone)
VIRGINIA DIODES INC.
321 West Main Street
Charlottesville, VA 22903-5537
(434)297-3257

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Jeffrey L Hesler
Hesler@VADiodes.com
321 West Main Street
Charlottesville, VA 22903-5537
(434)297-3257

TECHNICAL ABSTRACT (LIMIT 200 WORDS)
The best low-noise receiver solutions for frequencies above about 800 GHz rely on either a low-noise bolometric direct detector or a hot electron bolometric mixer. These receivers yield near quantum limited noise performance and have ultra broad signal bandwidth [ , , ]. However, due to their extreme sensitivity and inherently broad bandwidth the receivers are very sensitive to stray radiation. For direct detectors an input filter is required to define the receiver's frequency band and reject out of band energy. In the case of a heterodyne receiver, the signal band is defined by the back-end electronics, however, input filters are required to eliminate stray radiation that can saturate the mixer or create signal artifacts that degrade performance and prevent accurate calibration. Through this SBIR project VDI proposes to create a new generation of high performance and cost effective metal mesh filters for terahertz receivers based on innovative filter designs and fabrication techniques. These new technologies will allow the development of cost-effective and practical filters with the range of characteristics required for NASA's terahertz frequency space science and Earth science remote sensing programs.

POTENTIAL NASA COMMERCIAL APPLICATIONS (LIMIT 100 WORDS)
NASA's remote sensing programs for both Earth Science and Space Science require the development of low-noise receivers spanning the terahertz frequency range. Depending on the nature of the measurement to be made, either a direct detector or a heterodyne receiver will be required. However, both heterodyne receivers and direct detectors require input filters to limit the bandwidth of the energy coupled to the sensitive detector element. The innovative metal mesh filters to be developed will be the most versatile and cost efficient solution for this important application.

POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (LIMIT 100 WORDS)
Terahertz receivers are presently being developed for a wide range of scientific, military and commercial applications. Recently, this technology has been applied to both medical diagnostics and security applications. As an example of a potentially large commercial market, many research groups are now developing terahertz imaging systems based on direct detectors. These systems will require input filters to prevent stray signals from saturating the sensitive detectors and causing image degradation. The filters proposed in this NASA SBIR project would also be ideal for this application.