Massachusetts Institute of Technology

Boston University

Harold Young Hwang

Keith Adam Nelson

Richard Douglas Averitt

Kebin Fan

Aaron Sternbach

Mengkun Liu

Benjamin K Ofori-Okai

Jian Lu

Xian Li

Yaqing Zhang

Vladimir Bulovic

Wendi Chang

Brandt Christopher Pein

Nathaniel C Brandt

A nonlinear terahertz (THz) spectroscopy technique uses a sample illuminated by two THz pulses separately. The illumination generates two signals Band B, corresponding to the first and second THz pulse, respectively, after interaction with the sample. The interaction includes excitation of at least one ESR transition in the sample. The sample is also illuminated by the two THz pulses together, with an inter-pulse delay &#x3c4;, generating a third signal B. A nonlinear signal BNL is then derived via B=B&#x2212;B&#x2212;B. This nonlinear signal Bcan be then processed (e.g., Fourier transform) to study the properties of the sample.

Systems, apparatus, and methods of nonlinear terahertz (THz) magnetic resonance measurement

An apparatus for detecting electromagnetic radiation within a target frequency range is provided. The apparatus includes a substrate and one or more resonator structures disposed on the substrate. The substrate can be a dielectric or semiconductor material. Each of the one or more resonator structures has at least one dimension that is less than the wavelength of target electromagnetic radiation within the target frequency range, and each of the resonator structures includes at least two conductive structures separated by a spacing. Charge carriers are induced in the substrate near the spacing when the resonator structures are exposed to the target electromagnetic radiation. A measure of the change in conductivity of the substrate due to the induced charge carriers provides an indication of the presence of the target electromagnetic radiation.

Detection of electromagnetic radiation using nonlinear materials

A radiation detection technique employs field enhancing structures and electroluminescent materials to converts incident Terahertz (THz) radiation into visible light and/or infrared light. In this technique, the field-enhancing structures, such as split ring resonators or micro-slits, enhances the electric field of incoming THz light within a local area, where the electroluminescent material is applied. The enhanced electric field then induces the electroluminescent material to emit visible and/or infrared light via electroluminescent process. A detector such as avalanche photodiode can detect and measure the emitted light. This technique allows cost-effective detection of THz radiation at room temperatures.

Systems, methods, and apparatus for radiation detection

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Harold Young Hwang