Quasi-optical millimeter-wave characterization and application of high [Tc] superconducting thin films

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7303090

Zhang, D W

Transmission losses and phase changes were measured as a function of temperature at W-band frequencies from 75 to 110 GHz. Real and imaginary parts of the complex conductivities of YBCO superconducting thin films were calculated based on a simple multilayer transmission model. Frequency dependence of that peak was investigated from 75 to 110 HGz range. Millimeter wave surface resistance and penetration depth of the high Tc superconducting thin films were determined and compared with results of other millimeter-wave characterization techniques. These measurements were extended using quasi-optical millimeter wave bandpass filters using YBa[sub 2]Cu[sub 3]O[sub 7] high Tc superconducting films fabricated on MgO and LaAlO[sub 3] substrates. Transmission through the filter was investigated in the 75 to 110 GHz frequency range at temperatures from 15 to 300 K. Measurements of YBa[sub 2]Cu[sub 3]O[sub 7] filters were compared with similar filters fabricated using gold. For higher operation temperatures of those superconducting filters, 7000 [angstrom] Tl[sub 2]CaBa[sub 2]Cu[sub 2]O[sub 8] high Tc superconducting thin films on LaALO[sub 3] substrates were also utilized to fabricate both bandpass and bandstop filters at W-band. The optical response of Y Ba[sub 2]Cu[sub 3]O[sub 7] high Tc superconducting quasi-optical millimeter wave bandpass filters operating at W band (75-110 GHz) has been investigated under various conditions of illumination. Radiation from a cw Ar[sup +] laser (514.5 nm) and a frequency-doubled Nd:YAG laser (532.8 nm, 120 ps) was used to induce a shift in the resonant frequency of the filter. A shifted Lorentzian line shape function model was used to estimate the magnitude of the light-induced changes in the millimeter wave transmission. Shifts of the filter's resonance frequency on the order of 0.1 MHz were induced by the laser effects on the superconductor pair population.

• Research Organization: California Univ., Los Angeles, CA (United States)
• OSTI ID: 7303090
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
BARIUM COMPOUNDS
BARIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
CUPRATES
ELECTROMAGNETIC RADIATION
ENERGY LOSSES
FILMS
FREQUENCY RANGE
GHZ RANGE
HIGH-TC SUPERCONDUCTORS
INFRARED RADIATION
INTERMETALLIC COMPOUNDS
LOSSES
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
POWER LOSSES
RADIATIONS
SUPERCONDUCTING FILMS
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES