title: High-gain cryogenic amplifier assembly employing a commercial CMOS operational amplifier.
abstract: We have developed a cryogenic amplifier for the measurement of small current signals (10 fA-100 nA) from cryogenic optical detectors. Typically operated with gain near 10(7) V/A, the amplifier performs well from DC to greater than 30 kHz and exhibits noise level near the Johnson limit. Care has been taken in the design and materials to control heat flow and temperatures throughout the entire detector-amplifier assembly. A simple one-board version of the amplifier assembly dissipates 8 mW to our detector cryostat cold stage, and a two-board version can dissipate as little as 17 μW to the detector cold stage. With current noise baseline of about 10 fA/(Hz)(1/2), the cryogenic amplifier is generally useful for cooled infrared detectors, and using blocked impurity band detectors operated at 10 K, the amplifier enables noise power levels of 2.5 fW/(Hz)(1/2) for detection of optical wavelengths near 10 μm.
authors.affiliation: Jung Research and Development Corp., 3807 Porter St. NW #304, Washington, DC 20016, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Proctor
authors.affiliation: L-1 Standards and Technology, Inc., 209 High Street, New Windsor, Maryland 21776, USA.
authors.forename: A W
authors.initials: AW
authors.lastname: Smith
authors.affiliation: Jung Research and Development Corp., 3807 Porter St. NW #304, Washington, DC 20016, USA.
authors.forename: T M
authors.initials: TM
authors.lastname: Jung
authors.affiliation: National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA.
authors.forename: S I
authors.initials: SI
authors.lastname: Woods