Superconducting multiplexer for arrays of transition edge sensors

We report the design and testing of an analog superconducting time-division multiplexer to instrument large format arrays of low-temperature bolometers and microcalorimeters. The circuit is designed to multiplex an array of superconducting quantum interference devices, thereby simplifying wiring and room temperature electronics. We have fabricated a prototype 8×1 multiplexer chip and show a switching rate of 1 MHz. We calculate that a 32×32 array or larger is feasible.