Abstract

Superconducting thin films of YBa₂Cu₃O₇- are examined by measuring the second-harmonic-generated (SHG) signal from an incident 100 fs CPM laser pulse at 620 nm. The effects of film thickness, substrate, and oxygen content are investigated at room temperature in air and at low temperatures (20300 K) in a vacuum. Investigated films vary in thickness from 40 to 600 nm. At room temperature in air, an increase in SHG intensity with increasing film thickness is observed. A comparison is also made, under the same conditions, between the SHG intensity of a fully oxidized film and a partially oxidized film.

© 1990 Optical Society of America