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Nanoscale Spectroscopy with Applications to Chemistry
Published in Sarhan M. Musa, Nanoscale Spectroscopy with Applications, 2018
The resolution of optical setup of Raman system is defined by the lens or objectives used in the illumination/collection optics. One of the most important factors that dictate optical resolution is the diffraction limit of light. This forms the basis of the first challenge facing nanoscale Raman spectroscopy. This resolution limit also known as the phenomenon of limiting the resolution of optical elements was identified by Ernst Abbe, a German physicist, in the 1870s also known as the “Rayleigh criterion.” It defines the minimum distance “r” between two objects at which they are resolvable and is given by [1] () r≥1.22λ2nsinθ
Analog Capture
Published in Syed R. Rizvi, Microcontroller Programming, 2016
Most of us know that the display resolution of a digital television is the number of distinct pixels in each dimension that can be displayed. It is commonly believed that the higher the resolution, the better the quality of the image because more pixels can fit in each dimension. Optical resolution describes the ability of an imaging system to resolve detail in the object that is being imaged. But the resolution that we are concerned about in the discussion of ADC is not optical in nature. It is the resolution that is the relationship of each step to the range. Recall the computation of step voltage (VSTEP). Since we compute the step voltage by dividing the range (in volts) to the total number of steps in that range, we can easily say that step voltage is the resolution of the system in terms of volts. We repeat the VSTEP formula that we discussed earlier. VSTEP=(Range)/(Number of steps)=(VRH−VRL)/(2n)
Fourier Optics
Published in Toyohiko Yatagai, Fourier Theory in Optics and Optical Information Processing, 2022
The optical resolution is a measure of how fine object an optical system can resolve. It depends on the detection conditions. Because the object is observed by the eye or by an electro-optical detector, it is difficult to define in general.
The IMAT imaging camera
Published in Radiation Effects and Defects in Solids, 2022
The optical resolution of an imaging system mainly depends on the characteristics of the sensor used to acquire the images and on the magnification factor offered by the lens adopted, but it cannot be separated from a correct and accurate focusing of the system on the object to be captured. To evaluate the performance in terms of spatial resolution obtainable by the tomographic camera using the autofocusing system, it was decided to compare the theoretical spatial resolution value with that obtained experimentally. Using a lens with a focal length of 135 mm for the acquisition system, which provides a camera FOV of 50 × 50 mm2, and a 512 × 512 sensor, a theoretical spatial resolution of about 100 μm is obtained. The experimental measurement of the spatial resolution was carried out by capturing the focused image using the autofocusing system of the 1951 USAF Glass Slide Resolution Targets pattern. Figure 5 shows the image of the pattern acquired by the CCD, with two successive enlargements of the central part, from left to right.