THz detection by modified thermopile

Abstract

The modified micromachined thermopile consists of linearly arranged thermopairs instead of the usual loops. This device can act as a series of antennas and senses the millimeter wave radiation [1]. The antenna-like operation was demonstrated by the strong dependence on the polarization. The working principle is similar to the bolometers in that respect that the absorbed radiation heats up the semiconductor strips, but the temperature increment is sensed by the Seebeck effect instead of the resistance increment. Therefore there is no read-out current and the voltage output starts from zero. In the present work we are going to search absorption spectra of the device. It is shown that the resonance depends mainly on the dimensions and shape of the chip; the linear thermopiles are rather E-field probes. The fabrication of the device will be also outlined as well as the experimental results.