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Array of Bolometers for Submillimeter- Wavelength OperationA feed-horn-coupled monolithic array of micromesh bolometers is undergoing development for use in a photometric camera. The array is designed for conducting astrophysical observations in a wavelength band centered at 350 m. The bolometers are improved versions of previously developed bolometers comprising metalized Si3N4 micromesh radiation absorbers coupled with neutron- transmutation-doped Ge thermistors. Incident radiation heats the absorbers above a base temperature, changing the electrical resistance of each thermistor. In the present array of improved bolometers (see figure), the thermistors are attached to the micromesh absorbers by indium bump bonds and are addressed by use of lithographed, vapor-deposited electrical leads. This architecture reduces the heat capacity and minimizes the thermal conductivity to 1/20 and 1/300, respectively, of earlier versions of these detectors, with consequent improvement in sensitivity and speed of response. The micromesh bolometers, intended to operate under an optical background set by thermal emission from an ambient-temperature space-borne telescope, are designed such that the random arrival of photons ("photon noise") dominates the noise sources arising from the detector and readout electronics. The micromesh is designed to be a highly thermally and optically efficient absorber with a limiting response time of about 100 s. The absorber and thermistor heat capacity are minimized in order to give rapid speed of response. Due to the minimization of the absorber volume, the dominant source of heat capacity arises from the thermistor.
Document ID
Acquisition Source
Jet Propulsion Laboratory
Document Type
Other - NASA Tech Brief
Bock, James
(California Inst. of Tech. Pasadena, CA, United States)
Turner, Anthony
(California Inst. of Tech. Pasadena, CA, United States)
Date Acquired
August 24, 2013
Publication Date
February 1, 2007
Publication Information
Publication: NASA Tech Briefs, February 2007
Subject Category
Technology Utilization And Surface Transportation
Report/Patent Number
Distribution Limits
Public Use Permitted.
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