Variable temperature scanning laser microscopy of wider width high temperature superconducting films

We have investigated the spatial distribution of resistive properties in 2 mm wide and 10 mm long epitaxial superconducting films using a variable temperature scanning laser microscopy (VTSLM). This technique measures ac voltage of bolometric response created by a laser beam. We have observed the spatial nonuniformity of superconducting transition temperature in the resistive region, which has never been reported in samples wider than 300 /spl mu/m using scanning laser techniques. This result is a significant step toward developing VTSLM for coated conductor diagnosis.