Infrared detection with high-T_c bolometers and response of Nb tunnel junctions to picosecond voltage pulses

Thesis/Dissertation · Sat May 01 00:00:00 EDT 1993

DOI:https://doi.org/10.2172/10169798· OSTI ID:10169798

Verghese, Simon ^[1]

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1. Univ. of California, Berkeley, CA (United States)

Oxide superconductors with high critical temperature T_c make sensitive thermometers for several types of infrared bolometers. The authors built composite bolometers with YBa₂Cu₃O_7-δ thermometers on sapphire substrates which have higher sensitivity than competing thermal detectors which operate at temperatures above 77 K. A 1 x 1 mm bolometer with gold black serving as the radiation absorber has useful sensitivity for wavelengths 20--100 μm. A 3 x 3 mm bolometer with a bismuth film as the absorber operates from 20--100 μm. High-T_c bolometers which are fabricated with micromachining techniques on membranes of Si or Si₃N₄ have potential application to large-format arrays which are used for infrared imaging. A nonisothermal high-T_c bolometer can be fabricated on a membrane of yttria-stabilized zirconia (YSZ) which is in thermal contact with the heat sink along the perimeter of the membrane. A thermal analysis indicates that the YSZ membrane bolometer can have improved sensitivity compared to the sapphire bolometer for spectrometer applications. The quasiparticle tunneling current in a superconductor-insulator-superconductor (SIS) junction is highly nonlinear in the applied voltage. The authors have made the first measurement of the linear response of the quasiparticle current in a Nb/AlO_x/Nb junction over a broad bandwidth from 75--200 GHz. Nonlinear measurements made with these pulses may provide information about the quasiparticle lifetime. Preliminary data from such measurements are presented.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 10169798
• Report Number(s): LBL-34171; ON: DE93016963; TRN: 93:016659
• Resource Relation: Other Information: TH: Thesis (Ph.D.); PBD: May 1993
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
INFRARED RADIATION
RADIATION DETECTION
BOLOMETERS
DESIGN
SUPERCONDUCTING JUNCTIONS
RESPONSE FUNCTIONS
HIGH-TC SUPERCONDUCTORS
THERMOMETERS
SUBSTRATES
FABRICATION
YTTRIUM OXIDES
BARIUM OXIDES
COPPER OXIDES
SAPPHIRE
SENSITIVITY
BISMUTH
USES
ZIRCONIUM OXIDES
THERMAL ANALYSIS
SPECTROMETERS
TUNNEL EFFECT
NIOBIUM
NONLINEAR PROBLEMS
COMPARATIVE EVALUATIONS
EXPERIMENTAL DATA
QUASI PARTICLES
440500
665412
THERMAL INSTRUMENTATION
SUPERCONDUCTING DEVICES