Influence of Laser Processing Proximity on Superconducting Film Performance

Superconducting structures were designed and fabricated to evaluate the critical temperature (T
$_{c}$
) and the critical current density (J
$_{c}$
) before and after 400 fs pulsed laser exposure on and surrounding Nb traces (
$\sim$
250 nm thick). Dependence of laser exposure distance as close as 1 mm from the superconducting structure was explored and results comparing 1040 nm and 520 nm wavelength laser irradiation are demonstrated. A minimal change in T
$_{c}$
(
$\pm$
1.5%) and a significant increase in J
$_{c}$
(
$>$
10%) was observed when irradiating in proximity to a Nb trace. Effects of photon flux directly on a superconducting trace are detailed. A marginal decrease in T
$_{c}$
and J
$_{c}$
(
$< $
3%) was observed when directly irradiating a Nb trace below the ablation threshold. A significant decrease in T
$_{c}$
(
$>$
10%) and J
$_{c}$
(
$>$
90%) was observed when directly irradiating a Nb trace above the ablation threshold. Outcomes of this work establish guidance for safe laser processing conditions on and surrounding Nb traces to ensure minimal degradation of superconducting performance in process-sensitive superconducting electronics.