Comparison of visible and infrared spectrum of light sources

We compared the visible and the infrared spectrum of cesium and the sodium high pressure discharge light sources of 70 W power, run at different voltages from 180 to 240 V. Although the cesium discharge lamp exhibits remarkable white light in the visible spectrum, it suffers from the large infrared radiation intensity. The study of the causes of large infrared losses and their possible reduction was the main motivation for the present investigation. Sodium discharge plasma appears to be more efficient light source than the cesium discharge plasma due to the smaller infrared emission, although the latter has much better colour rendering index.     

The visible emission spectrum of iodine

The emission spectrum of iodine has been photographed in the visible region at high resolution, and 16 bands of the $\text{B[0}{}^{\mathrm{+}}\text{u(}{}^3\text{Π}\text{)] → X[0}{}^{\mathrm{+}}\text{g(}{}^1\text{Σ}\text{)]}$ system have been rotationall analyzed. Centrifugal distortion constants for the B state are calculated from the empirical (RKR) potential curve using a method which employs semiclassical phase integrals. The results of the rotational analysis are processed together with earlier results to yield improved spectroscopic parameters for the B state, valid for 3 < v′ < 40.     

The infrared spectrum of methylenimine

Eleven isotopic species of methylenimine have been prepared by the mercury-arc photolysis of methyl azide isolated in argon, nitrogen, and carbon dioxide matrices at 4 and at 14 K. Sufficient concentrations of methylenimine were obtained for identification of all of the vibrational fundamentals except the NH stretching mode. Using a recent ab initio structural calculation for this molecule, it has been possible to derive a set of valence-force potential constants which provide a satisfactory fit to all of the infrared spectroscopic data. The magnitude of the carbon-nitrogen stretching force constant is appropriate for a double bond. The temperature dependence of the thermodynamic properties of methylenimine has also been calculated.     

The infrared spectrum of GeO

The high-temperature infrared spectrum of the Δv = 1 sequence of GeO has been investigated from 882 to 955 cm⁻¹ with a tunable diode laser spectrometer. Transitions from ⁷⁰Ge¹⁶O, ⁷²Ge¹⁶O, ⁷³Ge¹⁶O, ⁷⁴Ge¹⁶O, and ⁷⁶Ge¹⁶O were measured for vibrational transitions from v = 1−0 to v = 6−5 and fit to a single set of eight Dunham potential coefficients.     

Electron-beam-pumped infrared and visible lasers

This paper presents the results of investigations of lasing by electronic transitions of xenon, krypton, and neon atoms, cadmium and zinc ions, and nitrogen molecules and by oscillatory transitions of HF molecules. The processes responsible for the efficiency of each of the lasers have been studied. The maximum radiation energies achieved are as follows: up to 200 J at λ∼2.8 μm for a mixture of H₂−SF₆, up to 100 J at λ-1.73 μm and up to 50 J at λ=2.03 μm for xenon, up to 3 J at λ=358 nm for a mixture of Ar−N₂, and up to 0.5 J at λ=585.5 nm for neon. Institute of High-Current Electronics, Siberian Division of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 34–44, April, 2000.     

The visible absorption spectrum of S2O

The visible absorption spectrum of S₂O vapor has been studied by spectrographic and laser optoacoustic techniques. Magnetic rotation spectroscopy was used to establish the triplet-singlet nature of the transition. Vibrational analysis gave ν′₁ = 1089, ν′₂ = 505, and ν′₃ = 332 cm⁻¹.     

The visible spectrum of rhodium monoxide: RhO and RhO

Spectroscopic observations are reported for rhodium monoxide from hollow-cathode emission and laser-induced fluorescence experiments. Eleven bands of Rh¹⁶O and 10 of Rh¹⁸O, from the [15.8]²Π-X⁴Σ⁻ (b) and [16.0]²Π-X⁴Σ⁻ (b) transitions, have been rotationally analyzed. The ground state constants have been determined as B₀ = 0.4132, λ₀ = −0.58 and γ₀ = −0.102, in cm⁻¹. Rotational and lambda doubling parameters in v = 0, 1, 2, and 3 excited state vibrational levels have also been determined.     

The infrared absorption spectrum of γ-phenylpyridine

The infrared absorption spectrum of-phenylpyridine has been recorded experimentally in the range 600–2000 cm^–1 and the fundamental frequencies and forms of the normal vibrations have been calculated using the valence force field. The experimental and calculated data show satisfactory agreement.In conclusion the authors wish to thank L. A. Gribov for assistance and discussion of the results.     

The infrared spectrum of the CO dimer

The infrared spectrum of (¹²C¹⁸O)₂ has been studied for the first time using a tunable diode laser spectrometer in the 2095 cm⁻¹ region to probe a pulsed supersonic jet expansion. Very dilute gas mixtures of CO in He were used, resulting in small consumption of ¹²C¹⁸O sample gas, as well as cold and simple spectra. The results were analyzed using a term value scheme to obtain model-independent energies for 7 rotational levels belonging to 2 stacks in the lower state, v_CO=0, and 22 levels belonging to 7 stacks in the upper state, v_CO=1. The two ground state isomers of the CO dimer were found to be separated by only 0.639 cm⁻¹ for (¹²C¹⁸O)₂. These results provide a foundation for future studies of the millimeter wave spectrum.     

可见与近红外波段光纤吸收的实验研究

对可见光和近红外波段内光纤的损耗进行了实验研究。采用光纤截断法对多色光在光纤传输过程的损耗进行了实验测量,得到了光纤在可见光波段内吸收系数对波长的变化关系。对在500nm到1000nm的波段内存在的多处光纤吸收峰值给出了相应的解释。     

可见与近红外波段光纤吸收的实验研究

对可见光和近红外波段内光纤的损耗进行了实验研究。采用光纤截断法对多色光在光纤传输过程的损耗进行了实验测量,得到了光纤在可见光波段内吸收系数对波长的变化关系。对在500nm到1000nm的波段内存在的多处光纤吸收峰值给出了相应的解释。     

氮化铝薄膜的红外吸收光谱和喇曼光谱的研究

本文报道用直流平面磁控溅射法在Si片上生长c轴高度择优取向AIN薄膜的光学特性.俄歇谱分析表明薄膜是高纯的.从红外吸收光谱上分析获得晶格振动纵、横模的频率分别为2.5×10~(13)HZ和1.8×10~(13)Hz.从喇曼光谱上分析获得AIN薄膜的光学声子频率为297、512、607、656、832cm~(-1).与几种已知的纤锌矿结构二元化合物的声子频率模式类比获得AIN的光学声子模式.进一步分析表明AIN是一种静电力大于原子间各向异性力的晶体,且声子的最高频率与r~(-3/2)N~(-1/2)成正比.     

New band systems of NiCl in the photographic infrared

High dispersion spectrograms of NiCl, in the photographic infrared (λ6350?λ8750Å) have shown the existence of five new band systems, designated as F, G, H, I and J. The bands in all the five systems are degraded to longer wavelengths. The F, G and I systems consist of single headed bands while H and J systems consist of double headed bands. Approximate vibrational constants have been determined from the vibrational analysis. The observed structure of the bands indicates doublet-doublet transitions, as in the visible band systems of NiCl.     

空间目标红外辐射特性研究

利用目标的红外光谱特性进行目标探测和识别是一种有效的方法。以空间卫星为目标,研究了其红外辐射特性形成的机理;利用所建立的数学模型,仿真了空间目标在探测面上所形成的红外光谱特性曲线;分析了模型中各参数对目标光谱特性的影响程度和卫星目标的红外光谱曲线。     

The high-resolution, jet-cooled infrared spectrum of pentafluoroethane

The jet-cooled spectrum of pentafluoroethane (C₂HF₅) has been recorded between 1100 and 1325 cm⁻¹ at a resolution of 0.0022 cm⁻¹. A rotational temperature of approximately 10 K was achieved by expanding 50 Torr of C₂HF₅ in 500 Torr of helium. Transitions belonging to five different fundamental vibrations have been assigned and fit to a Watson Hamiltonian: the ν₃ band at 1309.880494(189) cm⁻¹, ν₄ at 1200.734645(67) cm⁻¹, ν₅ at 1142.78147(33) cm⁻¹, ν₁₃ at 1223.334098(115) cm⁻¹, and ν₁₄ at 1147.394185(163) cm⁻¹. The fit of the ν₄ band has an rms deviation of 0.000436 cm⁻¹ compared to the uncertainty in the experimental line position of 0.0002 cm⁻¹. Satisfactory fits were achieved for the other four bands (ν₃, ν₅, ν₁₃, ν₁₄) at this cold temperature, with most of the centrifugal distortion constants fixed at the ground state values. Joint fits with previous work were attempted for the ν₄ and ν₁₃, successfully in the former case and unsuccessfully in the latter.     

The infrared spectrum of Cd3As2

We present new measurements of infrared reflectivity of Cd₃As₂ at 15 K. One plasmon and eleven phonon characteristics are determined by the fitting process that reveals weak dipolar moments in the structure.     

The ACE-FTS atlas of the infrared solar spectrum

The ACE-FTS is a space-borne Fourier transform spectrometer onboard SCISAT-1. The satellite was launched in August 2003 and since February 2004 the ACE-FTS has been performing solar occultation measurements in order to infer the chemical composition of the terrestrial atmosphere. The individual spectra recorded at the highest limb tangent altitudes (above 160 km) are by definition “high sun” spectra and contain no atmospheric contribution. In this work, an empirical solar spectrum covering the 700 to 4430 cm⁻¹ spectral range has been constructed from an average of 224,782 individual ACE-FTS solar spectra. Line assignments have been made for about 12,000 lines. The spectrum and two line lists are provided in the supplemental material attached to this work. Due to the excellent noise level achieved in the ACE-FTS solar atlas presented here, numerous weak absorption features are assigned which were not detectable in the ATMOS solar observations.