Peltier thermoelectric cooler improves both the signal-to-noise ratio and warm-up time of high-power LED induced fluorescence detector and application to aflatoxins

2021 ◽  
pp. 339392
Author(s):  
Shihao Lu ◽  
Yan Gao ◽  
Xuhui Geng ◽  
Yafeng Guan
Keyword(s):  
High Power ◽  
Signal To Noise Ratio ◽  
Thermoelectric Cooler ◽  
Signal To Noise ◽  
Fluorescence Detector ◽  
Warm Up ◽  
High Power Led ◽  
Noise Ratio

High power, high signal-to-noise ratio single-frequency 1μm Brillouin all-fiber laser

2016 ◽  
Author(s):  
Jing Wang ◽  
Yubin Hou ◽  
Qian Zhang ◽  
Dongchen Jin ◽  
Ruoyu Sun ◽  
...  
Keyword(s):  
Fiber Laser ◽  
High Power ◽  
Signal To Noise Ratio ◽  
Single Frequency ◽  
High Signal ◽  
Signal To Noise ◽  
Noise Ratio

High power high signal-to-noise ratio multiwavelength Raman fiber laser based on random distributed feedback

2017 ◽  
Vol 56 (11) ◽  
pp. 110304 ◽  
Author(s):  
Hanshuo Wu ◽  
Jiaxin Song ◽  
Wei Liu ◽  
Jiangmin Xu ◽  
Hanwei Zhang ◽  
...  
Keyword(s):  
Fiber Laser ◽  
High Power ◽  
Signal To Noise Ratio ◽  
Distributed Feedback ◽  
High Signal ◽  
Signal To Noise ◽  
Raman Fiber Laser ◽  
Noise Ratio

scholarly journals High-power, high signal-to-noise ratio single-frequency 1 μm Brillouin all-fiber laser

2015 ◽  
Vol 23 (22) ◽  
pp. 28978 ◽  
Author(s):  
Jing Wang ◽  
Yubin Hou ◽  
Qian Zhang ◽  
Dongchen Jin ◽  
Ruoyu Sun ◽  
...  
Keyword(s):  
Fiber Laser ◽  
High Power ◽  
Signal To Noise Ratio ◽  
Single Frequency ◽  
High Signal ◽  
Signal To Noise ◽  
Noise Ratio

Determination of the Best Emulsion for the Microscopy of Crystals

1981 ◽  
Vol 39 ◽  
pp. 32-33
Author(s):  
David A. Grano ◽  
Kenneth H. Downing
Keyword(s):  
Spatial Frequency ◽  
Information Transfer ◽  
Signal To Noise Ratio ◽  
Experimental Situation ◽  
Photographic Emulsion ◽  
Modulation Transfer ◽  
Signal To Noise ◽  
Frequency Space ◽  
Noise Ratio

The retrieval of high-resolution information from images of biological crystals depends, in part, on the use of the correct photographic emulsion. We have been investigating the information transfer properties of twelve emulsions with a view toward 1) characterizing the emulsions by a few, measurable quantities, and 2) identifying the “best” emulsion of those we have studied for use in any given experimental situation. Because our interests lie in the examination of crystalline specimens, we've chosen to evaluate an emulsion's signal-to-noise ratio (SNR) as a function of spatial frequency and use this as our critereon for determining the best emulsion.The signal-to-noise ratio in frequency space depends on several factors. First, the signal depends on the speed of the emulsion and its modulation transfer function (MTF). By procedures outlined in, MTF's have been found for all the emulsions tested and can be fit by an analytic expression 1/(1+(S/S0)2). Figure 1 shows the experimental data and fitted curve for an emulsion with a better than average MTF. A single parameter, the spatial frequency at which the transfer falls to 50% (S0), characterizes this curve.

Experiments in Bright-Field Imaging with Hollow-Cone Illumination

1981 ◽  
Vol 39 ◽  
pp. 226-227
Author(s):  
W. Kunath ◽  
K. Weiss ◽  
E. Zeitler
Keyword(s):  
Signal To Noise Ratio ◽  
Carbon Support ◽  
Electronic System ◽  
Optic Axis ◽  
Hollow Cone ◽  
Signal To Noise ◽  
Bright Field ◽  
Noise Ratio ◽  
Single Field ◽  
Field Imaging

Bright-field images taken with axial illumination show spurious high contrast patterns which obscure details smaller than 15 ° Hollow-cone illumination (HCI), however, reduces this disturbing granulation by statistical superposition and thus improves the signal-to-noise ratio. In this presentation we report on experiments aimed at selecting the proper amount of tilt and defocus for improvement of the signal-to-noise ratio by means of direct observation of the electron images on a TV monitor.Hollow-cone illumination is implemented in our microscope (single field condenser objective, Cs = .5 mm) by an electronic system which rotates the tilted beam about the optic axis. At low rates of revolution (one turn per second or so) a circular motion of the usual granulation in the image of a carbon support film can be observed on the TV monitor. The size of the granular structures and the radius of their orbits depend on both the conical tilt and defocus.

Sign in / Sign up

Export Citation Format

Share Document