The advantages of a four-term Sellmeier-equation fit to refractive indexes of recently produced fused silica are described. The four-term fit gives more accurate smoothing and interpolation of data than the three-term...
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The advantages of a four-term Sellmeier-equation fit to refractive indexes of recently produced fused silica are described. The four-term fit gives more accurate smoothing and interpolation of data than the three-term fit used previously and also indicates data of questionable accuracy. After the suspect data had been eliminated, fits with an average deviation of 4.3 · 10 −6 were obtained with both three- and four-term equations over the range 0.21–2.32 μ .
A simplified version of the MacAdam equation for color difference is presented. It is used in comparison with the Adams-Nickerson index for hypothetical colors in C. I. E. space and for colors of selected plastic samp...
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A simplified version of the MacAdam equation for color difference is presented. It is used in comparison with the Adams-Nickerson index for hypothetical colors in C. I. E. space and for colors of selected plastic samples. The two indexes disagree seriously except when the color difference involves differences in only one, and the same, chromaticity coordinate. Visual estimates of color differences shown by plastic samples show preferential agreement with the MacAdam index. The suggestion is made that this simplified MacAdam formula be given wider trial.
A general phenomenological theory of the static and dynamic behavior of bolometers is presented. The theory assumes as given the fundamental relations between the temperature and resistance of the bolometer, and the p...
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A general phenomenological theory of the static and dynamic behavior of bolometers is presented. The theory assumes as given the fundamental relations between the temperature and resistance of the bolometer, and the past history of the power dissipated within it. From these basic properties are derived a number of the properties of more immediate interest, such as electrical impedance, responsivity as a function of frequency, and the static load *** equivalent circuits are developed to represent the behavior of the bolometer as a function of frequency at a single operating point. A two-terminal equivalent circuit is described that represents the electrical impedance as a function of frequency. In order to represent the response of the bolometer to incident radiation as a function of frequency, a four-terminal equivalent circuit is *** electrical bridge is described that permits one to measure by purely electrical means the electrical response that a bolometer would have to radiation of any given time dependence, including radiation that varies sinusoidally. By purely electrical means and without the need of a radiation source (calibrated or otherwise), the bridge provides a precise measurement of the bolometer’s responsivity (output volts per watt of incident radiation) as a function of frequency. An electrical signal S ( t ) at the input of the bridge produces the same electrical output as would be produced in the normal use of the bolometer by a radiation signal with the same wave form as S ( t ).The presentation is in three parts: static performance; stability; and dynamic performance.
A general account is given of the way in which the aberration coefficients introduced by Buchdahl are made use of in the design of optical systems. Experience shows that for many applications the coefficients of third...
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A general account is given of the way in which the aberration coefficients introduced by Buchdahl are made use of in the design of optical systems. Experience shows that for many applications the coefficients of third, fifth, and seventh orders provide a new and adequate technique for the analysis of the correction state of a system, the understanding of the raison d’être of a particular type of system, and the differential correction of a rough design. The geometrical representation and classification of the individual terms of the aberration polynomials is discussed. The method is exemplified by excerpts from the design of a telephoto objective.
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