Experimental Investigation of a 220 GHz Planar Multiple Bridges Superconducting Switch

Paper in proceeding, 2016

We present preliminary measured responses of a planar superconducting on/off switch centred at the 220 GHz. The superconducting switch, comprising three niobium nitride (NbN) bridges, deposited across the slotline section of a back-to-back unilateral finline, made of a similar superconducting material. The transmission characteristics of the superconducting switch illuminated by a sub-millimetre source were measured using a superconductor-insulator-superconductor (SIS) chip as direct detector. The NbN bridges were switched from the superconducting state to the normal state by a bias current exceeding the critical current of the bridges. With this arrangement, we have measured a switching dynamic range of similar to 13 dB at 245 GHz, demonstrating the successful operation of the multiple NbN bridges planar superconducting on/off switch.