This invention is directed to a unique imaging microscope operating within the electromagnetic terahertz frequency regime for medical applications. Unlike optical spectroscopes that only measure the intensity of light at specific frequencies, the terahertz domain allows for the precise measurements of the refractive index and absorption coefficient of samples that interact with the terahertz waves. Various liquids and gases molecules interact within the terahertz frequency band and their unique resonance lines allow their molecular structure to be identified.

The continued development of optical communications requires fast information processing. Therefore, ultrafast, all-optical systems and switches for basic processing at both ends of an optical transmission line are replacing electronic systems. However, there are speed and fabrication limits on present all-optical switches imposed by the properties of the materials presently used. This technology provides an improved ultrafast high sensitivity all-optical switch made from a single-walled carbon nanotube.

Freely propagating terahertz pulses are usually measured by sampling techniques such as photoconductive antenna or electro-optical sampling. Although these sampling techniques provide good signal-to-noise ratios and adequate temporal resolution, they cannot be used for measurement on a single-shot basis. The present invention provides a system for measuring a terahertz frequency pulse propagating in a free-space optical path using an optical streak camera and an electro-optical modulator.

This technology relates to detecting radiation by directing an optical beam into a volume of gas, ionizing a portion of the volume of gas with the optical beam to produce a plasma, and then detecting an acoustic signal produced from an interaction of a radiation wave with the plasma. This technology relates to the phenomenon of enhanced acoustic emission from laser-induced plasma under the influence of a single-cycle terahertz pulse. Aspects of this technology bridge the unintentional gap between THz photonics and photo-acoustics.

This technology relates to a plasma diagnostic method by directing THz radiation into plasma and detecting an emission due to the interaction of the THz radiation with the plasma to characterize the plasma. Terahertz (THz) waves occupy a segment of the electromagnetic spectrum between the infrared and microwave bands. As such, they can be used for imaging and sensing in ways not possible with conventional technologies such as X-ray and microwave.

This technology relates to detecting terahertz radiation using an optical beam in a volume of gas. Ionizing a portion of the volume of gas with the optical beam produces a plasma and fluorescence is produced from an interaction of a radiation wave with the plasma. Information contained in the characteristics of the detected fluorescence can be used to characterize the radiation wave. Terahertz (THz) waves occupy a segment of the electromagnetic spectrum between the infrared and microwave bands.

Using air as an emitting medium to generate terahertz wave has attracted attention because of its potential applications for remote distance THz wave sensing and imaging. Yet, the cutting edge energy conversion efficiency of THz wave generation with optical method is extremely low. Researchers at Rensselaer have developed a method for generating amplified terahertz radiation that includes inducing a first volume of a gas to produce a seed plasma and emit pulsed seed terahertz radiation by focusing an optical seed beam in the first volume.

Using air as an emitting medium to generate terahertz wave has attracted attention because of its potential applications for remote distance THz wave sensing and imaging. Yet, the cutting edge energy conversion efficiency of THz wave generation with optical method is extremely low. Researchers at Rensselaer have developed a method for generating amplified terahertz radiation that includes inducing a first volume of a gas to produce a seed plasma and emit pulsed seed terahertz radiation by focusing an optical seed beam in the first volume.

Terahertz wave imaging has been used in various applications, such as security sensing and quality control inspection, for example. Terahertz wave two-dimensional (2D) imaging technology has been demonstrated as it dramatically reduces the time required for image acquisition. It can also support real-time terahertz wave imaging.

Terahertz (THz) waves occupy a segment of the electromagnetic spectrum between the infrared and microwave bands. As such, they can be used for imaging and sensing in ways not possible with conventional technologies such as X-ray and microwave. Because THz radiation transmits through almost anything that is not metal or liquid, the waves can see through most materials that might be used to conceal explosives or other materials, such as packaging, corrugated cardboard, clothing, shoes, backpacks, and book bags.