AC Bolometer Theory and Measurements of Kinetic Inductance Bolometer-Resonators

Abstract

AC bolometer theory is built on the established matrix formalism for quantum calorimeters and bolometers. The bolometer is represented by a 3 × 3 matrix with complex valued parameters. The bolometer matrix is used to model the behavior of the devices including the response to signal and noise, feedback, pulse response times, stability, and bolometer impedance. The effects of a current dependent bolometer impedance are included. The matrix simplifies theoretical computations of AC devices, including demodulation and the interactions between signals at different frequencies. This theory is applied to measurements of bolometers, each consisting of a kinetic inductance device suspended on a silicon nitride membrane. These measurements and analysis facilitate the optimization of the design and performance of these novel AC bolometers.