Active and accurate temperature control of terahertz functional devices using a micro-hotplate system

Abstract

Based on the problem where the intensity of an excitation source is not easy to regulate using the traditional active control method, this paper presents an accurate temperature control system based on a micro-hotplate for the first time. This system realizes the active control of terahertz functional devices, and implements various functions by using the proposed accurate temperature control process. The temperature control characteristics of the micro-hotplate are introduced into the design of terahertz functional devices by taking a vanadium dioxide (VO2) terahertz absorber as an example. In this design, a silicon-based micro-hotplate is used to heat the terahertz absorber. According to the phase transition characteristics of VO2, the alteration of temperature leads to a conductivity change, so as to realize the active control of the absorber. At the same time, this paper also analyzes the heating and cooling time of the micro-hotplate. The simulation results show that, by using the micro-hotplate to heat the terahertz functional devices, the temperature adjustment speed is reasonably high and the controllable performance is excellent. The test results show that the surface temperature can be controlled between 40 °C and 80 °C, and the temperature difference of the working area can be kept within 1 °C. The temperature control of the micro-hotplate is accurately controlled, resulting in excellent performance of the terahertz functional devices.