Quasioptical qualification of parallel/series arrays of cold-electron bolometers with a cross-slot antenna

TL;DR

This study evaluates the absorption efficiency, responsivity, and noise performance of parallel/series arrays of cold-electron bolometers integrated with a cross-slot antenna, combining experimental measurements and electromagnetic modeling.

Contribution

It introduces a combined experimental and theoretical approach to characterize and optimize bolometer arrays with a cross-slot antenna for improved detection performance.

Findings

Absorption efficiency and NEP measured with two independent methods

Difference between methods does not exceed 30%

Proposed setup optimization to achieve photon-limited detection

Abstract

We perform experimental and theoretical study of the parallel-series arrays of Cold-Electron Bolometers (CEBs) integrated into a cross-slot antenna and composed with an immersion silicon lens. The purpose is to determine the absorption efficiency, the responsivity and the noise equivalent power (NEP) of the bolometers. The absorbed power has been found in two independent ways. The comparison of two approaches gives better understanding of the system and secures from misinterpretations. The first approach is fitting of the bolometer IV curves with solutions of heat-balance equations. The second approach is modeling of electromagnetic properties of the system, including an antenna, lens, optical can, band-pass filters and black body source. The difference between both methods does not exceed $30\%$. The optimization of experimental setup is proposed to approach the photon limited detection mode.