Antenna coupled direct detector for millimetre and submillimetre astronomy based on 2D electron gas in semiconducting heterostructure

摘要

The energy resolution of a detector is related to the figure of merit NEP x ~τ~(1/2)which is proportional to the heatcapacity of the detector. Hot electron (cold electron) devices have much lower heat capacity than bolometers withsilicon nitride based thermal isolation. Traditional hot electron bolometers (HEB) require sub-micron fabricationfor use at submm wavelengths and it is difficult to simultaneously couple radiation and read out these devices. The 2D electron gas (2DEG) in a semiconductor heterojunction effectively acts as a metal film with a thicknessof a few angstroms and a tunable density and electron mobility. We describe a HEB that uses a 2DEG as anabsorber and present simulations of optical coupling schemes for this type of detector including an antennacoupled to a coplanar waveguide with distributed 2DEG absorbers.