We report the experimental observation of intrinsic dynamically localized vibrational states in crystals of the highly nonlinear halide-bridged mixed-valence transition metal complex ͕͓Pt͑en͒ 2 ͔ ͓Pt͑en͒ 2 Cl 2 ͔ ͑ClO 4 ͒ 4 ͖, where en ethylenediamine. These states are identified by the distinctive structure and strong redshifts they impose upon the overtone resonance Raman spectra. Quantitative modeling of the observed redshifts is presented based on a nonadiabatic coupled electron-lattice model that self-consistently predicts strong nonlinearity and highly localized multiquanta bound states.[S0031-9007(99)08915-2]

The SuperCam instrument suite provides the Mars 2020 rover, Perseverance, with a number of versatile remote-sensing techniques that can be used at long distance as well as within the robotic-arm workspace. These include laser-induced breakdown spectroscopy (LIBS), remote time-resolved Raman and luminescence spectroscopies, and visible and infrared (VISIR; separately referred to as VIS and IR) reflectance spectroscopy. A remote micro-imager (RMI) provides high-resolution color context imaging, and a microphone can be used as a stand-alone tool for environmental studies or to determine physical properties of rocks and soils from shock waves of laser-produced plasmas. SuperCam is built in three parts: The mast unit (MU), consisting of the laser, telescope, RMI, IR spectrometer, and associated electronics, is described in a companion paper. The on-board calibration targets are described in another companion paper. Here we describe SuperCam’s body unit (BU) and testing of the integrated instrument.The BU, mounted inside the rover body, receives light from the MU via a 5.8 m optical fiber. The light is split into three wavelength bands by a demultiplexer, and is routed via fiber bundles to three optical spectrometers, two of which (UV and violet; 245–340 and 385–465 nm) are crossed Czerny-Turner reflection spectrometers, nearly identical to their counterparts on ChemCam. The third is a high-efficiency transmission spectrometer containing an optical intensifier capable of gating exposures to 100 ns or longer, with variable delay times relative to the laser pulse. This spectrometer covers 535–853 nm ($105\text{--}7070~\text{cm}^{-1}$ 105 – 7070 cm − 1 Raman shift relative to the 532 nm green laser beam) with $12~\text{cm}^{-1}$ 12 cm − 1 full-width at half-maximum peak resolution in the Raman fingerprint region. The BU electronics boards interface with the rover and control the instrument, returning data to the rover. Thermal systems maintain a warm temperature during cruise to Mars to avoid contamination on the optics, and cool the detectors during operations on Mars.Results obtained with the integrated instrument demonstrate its capabilities for LIBS, for which a library of 332 standards was developed. Examples of Raman and VISIR spectroscopy are shown, demonstrating clear mineral identification with both techniques. Luminescence spectra demonstrate the utility of having both spectral and temporal dimensions. Finally, RMI and microphone tests on the rover demonstrate the capabilities of these subsystems as well.

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1977±1978 (ref. 23). A re-evaluation of systematic errors between GEOSECS and I8NR data is made by comparing deep-water values to determine the appropriate corrections before making the direct comparison for detecting the anthropogenic carbon signal.To determine the mean systematic difference between GEOSECS and I8NR, we compared samples from deeper than 2,000 m. First, the I8NR stations are organized into 6 groups corresponding to 6 stations occupied during the GEOSECS. Each group covers a range of 58 latitudes, with the centre location representing the re-occupation of GEOSECS stations. The mean concentration is computed for samples taken at 8 isopycnal surfaces and j v ranges from 27:75 6 0:01 to 27:82 6 0:01, which cover all samples from deeper than 2,000 m. The concentration difference along the same isopycnal surface at the same location between the two cruises is then computed. Results of the comparison are given in Table 1.We corrected the natural variations of DIC before making the intercomparison. The total carbon released into the water by the respiration of organic matter is estimated using the Red®eld ratio 12 C:O 2 of 117 6 14:170 6 10. The AOU-corrected DIC (DIC aou ) can be given as DIC aou DIC j 2 0:69 3 AOU, where DIC j is the observed DIC on an isopycnal surface. The choice of this Red®eld ratio is based on newer published results and has an insigni®cant effect on the magnitude of the detected CO 2 signal. If a ratio of 140/172, as derived from Indian Ocean 24 , is used, the signal will change by ,1 mmol kg -1 because the anthropogenic DIC increase is derived by difference of two data sets in which the same ratio is applied.The effect of changes in carbonate dissolution at two different times can be corrected by using Alk data. The DIC corrected for Alk (DIC alk ) is given by DIC alk DIC aou 2 0:5 3 Alk 2 Alk 0 , where Alk is the observed alkalinity for the isopycnal surface, and Alk 0 is the preformed salinity-normalized Alk, which can be calculated by using the empirical equation 25 : Alk 0 2;291 2 2:52t 2 20 0:06t 2 20 2 , where t is the potential temperature at the isopycnal horizon.To eliminate changes caused by the variations of salt, the corrected DIC is normalized to a salinity of 35.0: DIC n DIC alk =S 3 35:0, where DIC n is the salinity-normalized ®nal DIC value used for comparison between two different cruises.For estimating DIC increase from atmospheric CO 2 increase, the following needs to be considered. The potential temperature for waters at isopycnal surfaces between 26.6 and 27.2 ranges from 8 to 12 8C in the equatorial region and 6 to 13 8C in the temperature zone. Taking a mean potential temperature of 10 8C for this upper thermocline water, and a mean surface water alkalinity of 2,290 mmol kg -1 , the DIC at chemical equilibrium with the atmospheric CO 2 can be calculated. The rate of atmospheric CO 2 increase varies from 0.8 p.p.m. yr -1 in the early 1960s to ,1.8 p.p.m. yr -1 in recent years 26,27 . The DIC increase is computed using the rate of atmospheric CO 2 increase...

Solid-state optical refrigeration uses anti-Stokes fluorescence to cool macroscopic objects to cryogenic temperatures without vibrations. Crystals such as Yb3+-doped YLiF4 (YLF:Yb) have previously been laser-cooled to 91 K. In this study, we show for the first time laser cooling of a payload connected to a cooling crystal. A YLF:Yb crystal was placed inside a Herriott cell and pumped with a 1020-nm laser (47 W) to cool a HgCdTe sensor that is part of a working Fourier Transform Infrared (FTIR) spectrometer to 135 K. This first demonstration of an all-solid-state optical cryocooler was enabled by careful control of the various desired and undesired heat flows. Fluorescence heating of the payload was minimized by using a single-kink YLF thermal link between the YLF:Yb cooling crystal and the copper coldfinger that held the HgCdTe sensor. The adhesive-free bond between YLF and YLF:Yb showed excellent thermal reliability. This laser-cooled assembly was then supported by silica aerogel cylinders inside a vacuum clamshell to minimize undesired conductive and radiative heat loads from the warm surroundings. Our structure can serve as a baseline for future optical cryocooler devices.