Effects of laser irradiation on weak link devices

Experimental results will be presented on the effects of optical radiation impinging on superconducting weak links and films. In-house fabricated weak links of various materials showed a lowering of critical current values dependent on radiation intensity. Also, specially modified commercial SQUIDS showed a lowering of both dc bias and rf bias required for SQUID operation as the optical intensity was increased. We will discuss the possibility of using high Tc materials for SQUID fabrication and the "tuning" of these devices via optical irradiation.