Publications

Results 151–200 of 343

Search results

Jump to search filters

Terahertz near-field probe incorporating a λ/100 aperture for time-domain spectroscopy and imaging

Proceedings of SPIE - The International Society for Optical Engineering

Macfaden, Alexander J.; Reno, John L.; Brener, Igal; Mitrofanov, Oleg

Achieving high spatial resolutions for imaging with terahertz (THz) waves requires near-field probes, such as a sub-wavelength aperture probe. Bethe's theory of transmission through a sub-wavelength aperture of size a predicts that the transmitted electric field scales as Eαa3. This strong dependence limits the size of apertures that can be employed and hence the spatial resolution. This dependence however changes for the evanescent field components in very close proximity (∼1μm for THz waves) to the aperture, as shown by electromagnetic simulations. To exploit this effect in a THz near-field probe, we developed a photoconductive THz near-field detector structure, which incorporates a thinned photo-conductive detector region and a distributed Bragg reflector between the detector and the aperture plane. Near-field probes are manufactured with different aperture sizes to investigate transmission of THz pulses through apertures as small as 3μm. The experimental results confirm that the transmitted field amplitude, and therefore the sensitivity, increases by about one order of magnitude for the new probes. A 3μm aperture probe with a spatial resolution of λ/100 at 1THz is demonstrated.. © 2014 SPIE.

More Details
TYPE Conference YEAR 2014
ScopusOSTI

Transmission of THz pulses through 3μm apertures: Applications for near-field microscopy

Optics InfoBase Conference Papers

Macfaden, Alexander J.; Reno, John L.; Brener, Igal; Mitrofanov, Oleg

We demonstrate that THz pulses transmitted through small apertures (~λ/100) exhibit strong evanescent components within 1μm of the aperture. Using this effect, we developed subwavelength aperture THz near-field probes that provide 3μm resolution. © 2014 OSA.

More Details
TYPE Conference YEAR 2014
ScopusOSTI

Epsilon-near-zero subwavelength optoelectronics: Electrically tunable ENZ strong coupling

CLEO: QELS_Fundamental Science, CLEO:QELS FS 2013

Jun, Young C.; Reno, John L.; Sinclair, Michael B.; Brener, Igal

We demonstrate a new type of electrically tunable strong coupling between a planar metamaterial layer and an ultra-thin epsilon-near-zero layer made of a doped semiconductor. This can find novel applications in chip-scale infrared optoelectronic devices. © OSA 2013.

More Details
TYPE Conference YEAR 2013
OSTIScopus
Results 151–200 of 343
Results 151–200 of 343