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 (mu)m using scanning laser techniques. This result is a significant step toward developing VTSLM for coated conductor diagnosis.