High depth-of-field imaging without sacrificing light-gathering power and resolution

1997 ◽  
Author(s):  
Alan R. FitzGerrell ◽  
Edward R. Dowski, Jr.
1994 ◽  
Vol 161 ◽  
pp. 101-107
Author(s):  
U. Laux

The desire of astronomers for wide field telescope systems which surpass the RCC (1:8 max. 1.5 degree) in light gathering power and field of view are relative concrete today. For this type of telescope, detectors planned ARE CCDs in multichip arrangement.


2018 ◽  
Vol 89 (10) ◽  
pp. 103101 ◽  
Author(s):  
Hongbo Xie ◽  
Lirong He ◽  
Lei Yang ◽  
Chensheng Mao ◽  
Meng Zhu ◽  
...  

2019 ◽  
Vol 436 ◽  
pp. 232-238
Author(s):  
Xutao Mo ◽  
Tao Zhang ◽  
Bin Wang ◽  
Xianshan Huang ◽  
Cuifang Kuang ◽  
...  

2019 ◽  
Vol 12 (1) ◽  
pp. 523-543 ◽  
Author(s):  
Tom Wirtz ◽  
Olivier De Castro ◽  
Jean-Nicolas Audinot ◽  
Patrick Philipp

The helium ion microscope (HIM) has emerged as an instrument of choice for patterning, imaging and, more recently, analytics at the nanoscale. Here, we review secondary electron imaging on the HIM and the various methodologies and hardware components that have been developed to confer analytical capabilities to the HIM. Secondary electron–based imaging can be performed at resolutions down to 0.5 nm with high contrast, with high depth of field, and directly on insulating samples. Analytical methods include secondary electron hyperspectral imaging (SEHI), scanning transmission ion microscopy (STIM), backscattering spectrometry and, in particular, secondary ion mass spectrometry (SIMS). The SIMS system that was specifically designed for the HIM allows the detection of all elements, the differentiation between isotopes, and the detection of trace elements. It provides mass spectra, depth profiles, and 2D or 3D images with lateral resolutions down to 10 nm.


2003 ◽  
Vol 12 (2) ◽  
Author(s):  
G. Handler

AbstractI have investigated the value of the contribution of small telescopes to the success of a whole WET run. To this end, I have applied different data weighting schemes to two extreme WET test data sets. I find that weights proportional to the inverse local scatter in the light curves produce Fourier Transforms of best signal-to-noise. Weighting data stronger than their inverse scatter does not yield optimal results because of the reduction of the effective number of data points.The contribution of the small telescopes to the combined WET results was found to be very important. They do not only improve the spectral window, but they can reduce the noise in the total FT by more than their light gathering power would imply. Some suggestions for the optimal use of small telescopes in the WET are given.


During the past winter I have continued my studies on the spectrum of the night sky, and the connected subject of the auroral spectrum. The present paper reports the results obtained. The spectrographs used in this work are two of nearly identical construction. In designing them the paramount consideration was to obtain the greatest possible light gathering power, all other considerations being kept subordinate to this. It was accordingly decided to use the minimum number of optical pieces—one prism, one collimating lens, one camera lens, neither of the latter to be achromatic.


2015 ◽  
Vol 54 (11) ◽  
pp. 115103 ◽  
Author(s):  
Shouqian Chen ◽  
Van Nhu Le ◽  
Zhigang Fan ◽  
Hong Cam Tran

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