Performance Enhancement of Terahertz Laser Diode via Resonant Cavities

The recently developed terahertz laser diode (TLD) promised a high-power and integrable free-electron terahertz (THz) source, which has broad potential applications. However, the power and efficiency of the original TLD are restricted by the low quality factors of the operation modes. In this article, we propose an enhanced TLD boosted by resonant cavities, in which the quality factor of the resonant modes is remarkably increased, and the output power is enhanced by more than an order of magnitude. In addition, the operation modes together with the operation frequency of the device can be adjusted by changing the shape of the cavity so that TLD can efficiently operate with high-order mode, increasing the output frequency without enhancing the difficulty of machining, which is attractive for developing high-power and high-frequency free-electron THz sources.