Title :
High-speed optical detectors in YBCO films with non-granular and fine-grain morphologies
Author :
Tang, Q. ; Driessen, A. ; Hilderink, L.H. ; IJsselsteijn, R.P.J. ; Folkstra, J. ; Popma, T.J.A.
Author_Institution :
Dept. of Appl. Phys., Twente Univ., Enschede, Netherlands
fDate :
3/1/1993 12:00:00 AM
Abstract :
Optical detectors based on YBa/sub 2/Cu/sub 3/O/sub 7- delta / thin films have been fabricated, which show a response time of a few ns. Typical dimensions of the active area are 10 mu m*10 mu m. No preamplifier is needed during operation. The authors report on the optical response of detectors having nongranular and fine-grain morphologies to different sources of pulsed laser radiation (e.g., mode-locked Nd:YLF laser at 1.3 mu m and a GaAs diode laser at 0.9 mu m). Emphasis in the study is placed on detection sensitivity for measuring short optical pulses. It is found that the best noise obtained with a fine-grain detector is on the order of 10/sup -10/ W/Hz/sup 1/2/, when irradiated by the 65-ns-pulsewidth diode laser.<>
Keywords :
barium compounds; high-temperature superconductors; photodetectors; superconducting junction devices; superconducting thin films; yttrium compounds; YBCO films; YBa/sub 2/Cu/sub 3/O/sub 7- delta /; detection sensitivity; fine-grain morphologies; high temperature superconductor; nongranular; optical detectors; short optical pulses; Delay; Diode lasers; High speed optical techniques; Laser mode locking; Laser noise; Optical detectors; Optical films; Optical pulses; Preamplifiers; Yttrium barium copper oxide;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
