Total internal reflection (TIR) Raman spectroscopy is an experimentally straightforward, surface-sensitive technique for obtaining chemically specific spectroscopic information from a region within approximately 100-200 nm of a surface. While TIR Raman spectroscopy has long been overshadowed by surface-enhanced Raman scattering, with modern instrumentation TIR Raman spectra can be acquired from...

A spectrophotometer based on an integrating sphere coupled to a commercial Fourier Transform Infrared (FTIR) instrument has been constructed for regular spectral transmittance and re ectance measurements over the 1 m m to 18 m m wavelength region. Despite the large number of sources of error that often limit the radiometric accuracy of FTIR measurements, we demonstrate uncertainties similar to...

Spectrofluorometric methods of analysis are the most commonly analytical techniques and continue to enjoy wide popularity. The wide availability of the instrumentation, the simplicity of procedure, sensitivity, selectivity, precision, accuracy, and speed of the technique still make the spectrofluorometric methods attractive. These features make fluorescence spectroscopy an attractive technique ...

Abstract The Mid-Infrared Instrument (MIRI) extends the reach of James Webb Space Telescope (JWST) to 28.5 μ m. It provides subarcsecond-resolution imaging, high sensitivity coronagraphy, and spectroscopy at resolutions λ /Δ ∼ 100–3500, with high-resolution mode employing an integral field unit provide spatial data cubes. resulting broad suite capabilities will enable huge advances in studies o...

For resolving absolute concentration of tissue chromophores in the human adult brain with near-infrared spectroscopy it is necessary to calculate the light scattering and absorption, at multiple wavelengths with some depth resolution. To achieve this we propose an instrumentation configuration that combines multi-distance frequency and broadband spectrometers to quantify chromophores in turbid ...

Advances in instrumentation are making Raman spectroscopy the tool of choice for an increasing number of (bio)chemical applications. Raman is an interesting option for several reasons, including the sensitivity to small structural changes, non-invasive sampling capability, minimal sample preparation, and high spatial resolution in the case of Raman micro-spectroscopy. Herein we discuss the most...

针对大口径干涉型红外光谱辐射计, 分析了不平行于主光轴的入射光, 对理想仪器线型函数的影响. 本文系统介绍了对仪器线型函数产生影响的截断效应、有限视场效应、离轴效应和离焦效应, 并通过HITRAN数据库对理想的水汽吸收光谱进行仿真, 建立了仪器线型函数误差与光谱畸变的定量关系. 根据仿真结果, 提出了因子权重校正算法. 利用水汽吸收的仿真数据对因子权重校正算法进行验证, 光谱漂移从0.51 cm–1降低到0.01 cm–1以下. 通过自研干涉型红外光谱辐射计对标准黑体的观测实验, 验证因子权重校正算法的准确性, 实测数据的光谱漂移从0.226 cm–1降低到0.012 cm–1, 校正后的光谱数据更为准确.

Modern, high-brightness electron beams such as those from plasma wakefield accelerators and free-electron laser linacs continue the drive to ever-shorter bunch durations. In low-charge operation (~20 pC), bunches shorter than 10 fs are reported at the Linac Coherent Light Source (LCLS). Though suffering from a loss of phase information, spectral diagnostics remain appealing as compact, low-cost...