Realization of a quasi-commercial Terahertz detector

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 1 nW/√Hz and a −3 dB bandwidth of 6,8 Hz.