Resonant tunneling diode as high speed optical/electronic transmitter

We report both electronic and opto-electronic resonant tunneling diode (RTD) oscillators with relatively high output power. Electronic RTD oscillators working at 125/156/308 GHz with around one half milliwatt output power and optoelectronic oscillators in the 30-105 GHz range with about 1 mW output power at 44 GHz have been developed. First wireless transmission experiments with a 300 GHz oscillator are also reported.

I. Introduction

Terahertz (THz) technology has wide applications in such as security imaging, ultrafast wireless communication, spectroscopy systems, etc. [1]. Due to the lack of compact and high power THz sources operating at room temperature, the THz frequency is the less developed spectrum, especially in the 0.1 – 3 THz range. The resonant tunneling diode (RTD) has received considerable attention recently for realizing THz sources [2], [3]. Of all present solid-state sources, it has the highest demonstrated oscillation frequency of 1.92 THz [3]. Other advantages of the RTD include room temperature operation, compact size, and potential for optical control, among others. To be useful for practically relevant applications, output power levels of at least 1 mW at 300 GHz and at 1 THz are desirable [4], but these are yet to be demonstrated in RTD technology.