Structurally integrated thermal management for solid-state terahertz devices with high environmental stability

We present a structurally integrated thermal-management approach for solid-state terahertz frequency doublers that enhances both efficiency and environmental stability. By directly connecting the diode pads to the metal waveguide cavity, a low-thermal-resistance path is formed, lowering the simulated junction temperature by approximately 24 °C compared with conventional beam-lead packaging. A 170-260 GHz doubler has been designed, fabricated, and characterized. With an input power of up to 23.5 mW at 25 °C, the device achieves a broadband conversion efficiency of 8.06-16.43%, with a peak of 16.43% at 256 GHz. Characterization confirms that this efficiency remains stable over an ambient temperature range of 0 to 80 °C. This structurally integrated scheme mitigates self-heating and offers a scalable route to robust THz multipliers for communication, imaging, and sensing.