Terahertz technology promises myriad applications including imaging, spectroscopy and communications. However, one major bottleneck at present for advancing this field is the lack of efficient devices to manipulate the terahertz electromagnetic waves. Here we demonstrate that exceptionally efficient broadband modulation of terahertz waves at room temperature can be realized using graphene with ...

Terahertz quantum cascade laser sources based on intra-cavity difference-frequency generation are currently the only room-temperature mass-producible diode-laser-like emitters of coherent 1-6 THz radiation. Device performance has improved dramatically over the past few years to reach milliwatt-level power output and broad tuning from 1.2 to 5.9 THz, all at room-temperature. Terahertz output in ...

We use electric field singularities in biased metal semiconductor microstructures to enhance the generation of terahertz (THz) radiation from semiconductors. We find that, regardless of the mechanism that is responsible for enhanced THz emission near the anode, singular electric fields near sharp anode features will enhance this emission by as much as an order of magnitude. We show scanning THz...

Abstract Conceived over 30 years ago, photoconductive (PC) emitters have proved essential in the development and spread of terahertz technology. Since then, not only they been used extensively a wide range spectroscopic imaging applications, also undergone significant improvements performance, leading to their use for broadband or non-linear spectroscopy. In this review article, we provide an o...

Using recently-developed THz emitters constructed from single crystals of the high-Tc superconductor Bi2Sr2CaCu2O8+δ, we performed three prototype tests of the devices to demonstrate their unique characteristic properties for various practical applications. The first is a compact and simple transmission type of THz imaging system using a Stirling cryocooler. The second is a high-resolution Mich...

Controlling the longitudinal distribution in an electron beam traveling through an accelerator can enhance system performance in various ways. Prebunching an electron beam in an accelerator can lead to enhanced radiation production from various emitters. Smoothing the shape of the electron beam pulse may suppress instabilities that result in beam breakup. This work, a collaboration between the ...