In 1917, Albert Einstein was thinking about photons and excited atoms. There will always be some blurring of images, no matter what the size of the aperture or the wavelength of light used to make an image. Parameters for the Grating Scattered-Light Measurements aPerfect resolution is impossible. The average uncertainty for each parameter is 10–20%. Note that the UARS SOLSTICE F and N channels used an ISA grating and the G channel used a B&L grating however, the measurements at the unit level are not the gratings used in the SOLSTICE spectrometers. All these unit-level measurements were taken with a green He–Ne laser (λ = 543.5 nm) except for one measurement of the PE-6 grating taken with a red He–Ne laser (λ = 632.8 nm). The maximum number of grooves illuminated ( N max) sets a bound for N and is the theoretical value for N if the grating grooves are perfectly periodic and continuous with no interruptions such as surface imperfections. In counting the imperfections on the gratings, we considered the larger blemishes as three pinpoint imperfections, and the scratches were considered equivalent to 10 pinpoint imperfections.Ī The parameters for the GDF are the effective number of grating grooves N, the ratio of groove width to groove spacing f, and the constant background amplitude A B. (1) for the unit-level, scattered-light measurements. The blaze wavelength selection for a holographic grating is limited because of the blazing technique of using the grating groove height in determining the relative grating efficiency. The upper and lower halves of the PE TOMS gratings were characterized separately. All the gratings are plane gratings, and the substrates are square. © 1994 Optical Society of America Full Article |Ī These gratings are holographically ruled gratings except for the B&L grating, which is mechanically ruled. It was also discovered that multiple replicas of gratings from the same master grating exhibit significantly more scattered light than the preceding replica by factors of 1.1–2. The Lorentzian component is predicted from the diffraction theory for a grating, and the constant background component is consistent with Rayleigh scattering from the microscopic surface imperfections. It has been found from these measurements that there are two components of the grating scattered light: a Lorentzian-type component and a constant background component. The results from measuring the scattered-light properties of 10 diffraction gratings are discussed along with the application of these results in analyzing the total scattered light measured for three spectrometers. For a diffraction-grating spectrometer the primary contribution to instrumental scattered light has been found to be the scattered light from the grating. The scattered light can arise from any optical surface, and light leaks or scattering from baffles can also contribute to the instrumental stray-light level. One of the many calibrations performed for a scientific-quality spectrometer is the characterization of its scattered-light properties. Note: Author names will be searched in the keywords field, also, but that may find papers where the person is mentioned, rather than papers they authored.Use a comma to separate multiple people: J Smith, RL Jones, Macarthur.Use these formats for best results: Smith or J Smith. ![]()
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