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We present the results of a recent, extensive measurement campaign validating the traceability of the solar irradiance record and Earth radiation budget data. The campaign also established future traceability, thus ensuring confidence in the continuing climate-data record. The total solar irradiance radiometer facility (TRF) at the Laboratory for Atmospheric and Space Physics (LASP) Boulder, uses a liquid helium cooled cryogenic radiometer as the reference standard for the validation of spaceflight total solar irradiance (TSI) instrumentation. In 2008 the radiometer was directly compared to the National Institute of Standards and Technology (NIST) Primary Optical Watt Radiometer (POWR) at a wavelength of 532.12 nm. At TSI power levels, a correction factor of 1.000 306 with an associated standard uncertainty (u) of 0.000 098, was reported for the TRF radiometer scale when using external voltage measurement electronics, and not correcting for cavity heating non-equivalence or cavity absorptance. The TRF radiometer has recently been revalidated at LASP using a POWR calibrated silicon photodiode trap transfer standard named TT4. We report a correction factor of 0.999 787, u = 0.000 285 to align the TRF radiometer scale with the current NIST POWR scale. A new room temperature reference standard radiometer was established. It measured 133 parts per million (ppm) higher than POWR using the same silicon transfer standard as above, and in a separate direct measurement, 168 ppm lower than the TRF radiometer shuttered at 400 s full shutter cycle. The difference agrees within stated uncertainties. A correction of 0.999 867, u = 0.000 247 will align the new radiometer scale with the NIST radiant power scale of POWR.

We report novel, unusual effects in sub-λ spinplasmonic media using THz-TDS. THz field shape, amplitude, hysteretic effects, and time delay are sensitive to surface magnetization states and ferromagnetic/non-ferromagnetic (F/N) metallic junctions.

The application of THz plasmonics in imaging dielectric objects embedded in the metallic media is presented. Signatures of the embedded object was detected when the time domain information of the transmitted pulse was analyzed by THz time domain spectroscop y. The resolution of the acquired images was enhanced by using a super-resolution image processing technique. It is further shown that the images acquired from the pulse arrival time and phase magnitude reveal more details of the embedded object compared to the pulse power information. Keywords: Terahertz imaging, terahertz spectroscopy, plasmonics, super-resolution 1. INTRODUCTION From Hu and Nuss’ first pioneering experiments in 1995 1 , Terahertz (THz) imaging has evolved into one of the most practical applications of THz time-domain spectroscopy (THz-TDS). THz-TDS owes its continuing success to properties such as being broadband, sub-picosecond temporal resolution and phase sensitive coherent detection combined with the innate properties of a variety of dielectric materials. THz-TD S has been proven to be very successful for object and spectral imaging in a number of different fields, such as drug identification

Terahertz plasmonics application in imaging dielectrics embedded in metal-filled media is presented. Signatures of the objects were observed by exploiting the time domain information and the quality of acquired images was enhanced using image processing.

We demonstrate the terahertz frequency plasmonic characteristics of a metallic/semiconductor interface. The high-frequency transmission of terahertz radiation through dense ensembles of subwavelength sized Cu/CuxO microparticles via near-field coupling of localized plasmons is shown to increase when a CuxO/Au or CuxO/Pt interface is introduced. This finding introduces a previously undocumented characteristic of plasmonic interaction with material interfaces, and lays the physical groundwork for the integration of plasmonic circuits with traditional semiconductor electronics.

We present the application of THz plasmonics in imaging dielectric objects embedded in metal-filled media. By exploiting the time domain information from the transmitted pulse, signatures of the objects were observed. To enhance the low quality images acquired through THz time domain spectroscopy, a super-resolution image processing technique was applied. It is shown that pulse arrival time and phase magnitude information compared to the integrated instantaneous power of the transmitted pulse provides more detailed images of the embedded object.