A quasi-commercial Terahertz detector based on MIR thermopiles

TL;DR

This paper presents a compact, integrated Terahertz detector using MIR thermopiles and low power amplifiers, demonstrating high dynamic range, low NEP, and practical advantages over Golay cell detectors.

Contribution

The development and characterization of a novel integrated Terahertz detector based on thermopiles with superior dynamic range and sensitivity compared to existing Golay cell detectors.

Findings

High responsivity and bandwidth measured in THz CW setup

Dynamic range up to 100 mW incident power

NEP below 1 nW/√Hz with -3 dB bandwidth of 6.8 Hz

Abstract

Integrating a thermopile with a low power operational amplifier is an effective and cost-efficient approach to obtain a high performance compact Terahertz power detector. Here we present the development of such an integrated detector, including the fundamental building blocks, the final realization and related characterization. The responsivity and bandwidth of the detector are measured in a standard THz CW setup consisting of a closed cycle helium cryostat and a Quantum Cascade Laser (QCL). The predicted results are compared with measured data, showing a good agreement. Advantages of existing Golay cell THz detectors in both sensitivity and NEP figure vanish, in practical use, due to the enormous increment in dynamic range provided by the linear operation of the thermopile up to 100 mW of incident power while offering a NEP below 1nW/sqrt(Hz) and a -3dB bandwidth of 6,8 Hz.