C++ code for inverse solution of Monte Carlo calculation of optical scattering in single-layer material, i.e., determination of optical scattering parameters from the Angle-Resolved Scattering Described in RH Streater, A-MR Lieberson, AL Pintar. and ZH Levine, "A parallel version of MCML and an Inverse Monte Carlo Algorithm to Calculate Optical Scattering Parameters," J. Res. NIST, https://doi.org/10.6028/jresnist.122.038. See also the main article RH Streater, A-MR Lieberson, AL Pintar, CC Cooksey, and P Lemaillet, unpublished.

C++ code for Monte Carlo calculation of optical scattering in multi-layer material. Described in RH Streater, A-MR Lieberson, AL Pintar. and ZH Levine, "A parallel version of MCML and an Inverse Monte Carlo Algorithm to Calculate Optical Scattering Parameters," J. Res. NIST, https://doi.org/10.6028/jresnist.122.038. See also the main article RH Streater, A-MR Lieberson, AL Pintar, CC Cooksey, and P Lemaillet, unpublished.

Software to predict the optical sorting of particles in a standing-wave laser interference field

Rydberg atom-based receivers of modulated radio frequency (RF) fields are promising systems for measurements. These systems are self-calibrating, widely tunable, nearly transparent to RF fields, and can be electrically small. However, the instantaneous bandwidth of current Rydberg atom receivers is typically less than 1 MHz. Using two-photon electromagnetically induced transparency (EIT) to observe the 56D5/2 Rydberg state in cesium, we measure modulation sidebands on each tooth in a probe optical frequency comb that spans the D2 F=4-F'=5 transition resulting from transmission modulation of the probe beam. This transmission modulation occurs from changes in susceptibility of the room temperature cesium vapor as two RF fields impinge on the atoms. A strong RF local oscillator is resonant with the 56D-57P state and mixes with a weak RF signal field detuned from the RF LO by an intermediate frequency. Using a self-heterodyned electro-optic comb setup, we separate positive and negative sideband amplitudes and compare to an equivalent comb-free system. These data report EIT measurement with the comb system, local spectra around two comb teeth - one within and one outside the EIT line, and normalized minimum detectable RF signal field as a function of RF intermediate frequency used to evaluate the instantaneous bandwidth of the single frequency, positive sideband, and negative sideband datasets.

Deep subwavelength RF imaging with atomic Rydberg sensors has overcome fundamental limitations of traditionalantennas and enabled ultra-wideband detection of omni-directional time varying fields all in a compactform factor. However, in most applications, Rydberg sensors require the use of a secondary strong RF referencefield to serve as a phase reference. Here, we demonstrate a new type of Rydberg sensor for Angle-of-Arrival(AoA) sensing which utilizes subwavelength imaging of standing wave fields. By placing a metallic plate withinthe Rydberg cell, we can determine the AoA independent of the strength of incoming RF field and without requiringa secondary strong RF phase reference field. We perform precision AoA measurements with a roboticantenna positioning system for 4.2, 5.0, and 5.7 GHz signals and demonstrate a 1.7◦ polar angular resolutionfrom 0◦ to 60◦ AoA and 4.1◦ over all possible angles.

The dataset contains several MATLAB files and input files for the software package JCMsuite that enable the modeling of optical imaging of finite multi-line arrays.

This data was used for main results for the paper entitled "Coherent Optical Clock Down-Conversion for Microwave Frequencies with 10-18 Instability". We could calculate relative phase fluctuation and Allan deviation for both Yb optical clocks and 10 GHz microwaves. Uncertainty of our down-conversion system was also calculated from this.

The NIST Database for the Simulation of Electron Spectra for Surface Analysis (SESSA) can be used to simulate Auger-electron spectra and X-ray photoelectron spectra of nanostructures such as islands, lines, spheres, and layered spheres on surfaces. As for earlier versions, such simulations can be performed for multilayer films. Users can specify the compositions and dimensions of each material in the sample structure as well as the measurement configuration. The database contains extensive physical data needed for quantitative interpretations of observed spectra. A more detailed description of SESSA has been published [W. Smekal, W. S. M. Werner, and C. J. Powell Surf. Interface Anal. 37, 1059 (2005)].

Improving the bandwidth of Rydberg atom-based receivers is an ongoing challenge owing to the long-lived Rydberg state lifetimes that limit the refresh rate of ground state atoms.In particular, the LO-based Rydberg mixer approach allows for bandwidths into the few-MHz range.Here we use heterodyne detection of the Rydberg atom receiver probe laser to separate the negative and positive sidebands that originate from distinct six wave mixing processes in order to investigate their individual bandwidths.We experimentally confirm the prediction that the negative sideband exhibits a higher bandwidth than the positive sideband.We further explore the effect of coupling and probe laser Rabi frequency on the bandwidth, which we find to be in good agreement with our model. We achieved a maximum experimental (and theoretical) bandwidth of about 11 (11)~MHz and 3.5 (5)~MHz for the negative and positive sidebands, respectively, from the -3dB roll-off point for optimized field parameters.This work provides insight into the bandwidth-limiting features of Rydberg atom receivers and points the way towards further optimization of their response.

"We are proposing a new concept of integrated component development technology at submillimeter wavelengths that will dramatically simplify the fabrication, assembly, and integration of large focal plane arrays and imagers. This technology has the potential to significantly increase the pixel count of detector arrays and reduce the mass, volume, and complexity of array receivers for a broad range of applications in astrophysics and earth sciences. We will develop and demonstrate a highly integrated silicon-micromachined array receiver at 1.9 THz based on advanced dual-polarized, sideband-separating, balanced heterodyne mixers. The receiver front-end will be integrated with a novel micro-lens antenna array. We will design full-waveguide-band 90-degree quadrature hybrids, orthomode transducers (OMT), polarization twists, in-phase power splitters, and directional couplers at 1.9 THz; fabricate them using deep reactive ion etching (DRIE) based silicon micromachining, integrate them with existing HEB mixers at 1.9 THz; and test and fully characterize them in our laboratory. The scientific importance of high-resolution spectroscopic observations at submillimeter wavelengths is underscored by the key role of heterodyne spectrometers in the ESA cornerstone Herschel Space Observatory as well as the ground-based ALMA and airborne SOFIA. Star formation and key phases of galaxy evolution occur in region enshrouded by dust that obscures them at infrared and optical wavelengths, while the temperature range of the interstellar medium of ten to a few thousand Kelvin in these regions excites a wealth of submillimeter-wave spectral lines. With high-resolution spectroscopy, resolved line profiles reveal the dynamics of star formation, directly revealing details of turbulence, outflows, and core collapse. Observations of emission from ionized species such as C+ at 1900.53690 GHz (158 um), allow one to directly measure the cooling of the diffuse component of the interstellar m