A terahertz and infrared sensitive photomultiplier tube with a fieldmixing photocathode

摘要

In this work, we present a photomultiplier tube (PMT) with a metasurface photocathode that is based on ultrafast field emission (FE) from incident terahertz (THz)- and infrared (IR) light. We mix the incident electric field with the electric field from an electronic source to decrease the PMT detection threshold. Due to the pronounced non-linearity of FE, this approach allows for extremely sensitive light detection - possibly down to few or even single photon level across the entire THz- and IR frequency range.