Power spectrum of fibre output fluctuation in polarisation-preserving optical fibres

1984 ◽  
Vol 20 (22) ◽  
pp. 923 ◽  
Author(s):  
J. Sakai ◽  
M. Shimizu
Keyword(s):  
Power Spectrum ◽  
Optical Fibres ◽  
Fibre Output

Power spectrum of microbends in monomode optical fibres

1982 ◽  
Vol 18 (11) ◽  
pp. 448 ◽  
Author(s):  
K.J. Blow ◽  
N.J. Doran ◽  
S. Hornung
Keyword(s):  
Power Spectrum ◽  
Optical Fibres

The on-line use of histogram data for high-speed correction and alignment of electron microscope images

1984 ◽  
Vol 42 ◽  
pp. 556-557
Author(s):  
William Krakow
Keyword(s):  
Power Spectrum ◽  
High Speed ◽  
Direct Memory Access ◽  
Digital Television ◽  
Contrast Transfer Function ◽  
The Past ◽  
High Resolution Tem ◽  
On Line ◽  
Correction Of Astigmatism ◽  
The Fourier Transform

In the past few years on-line digital television frame store devices coupled to computers have been employed to attempt to measure the microscope parameters of defocus and astigmatism. The ultimate goal of such tasks is to fully adjust the operating parameters of the microscope and obtain an optimum image for viewing in terms of its information content. The initial approach to this problem, for high resolution TEM imaging, was to obtain the power spectrum from the Fourier transform of an image, find the contrast transfer function oscillation maxima, and subsequently correct the image. This technique requires a fast computer, a direct memory access device and even an array processor to accomplish these tasks on limited size arrays in a few seconds per image. It is not clear that the power spectrum could be used for more than defocus correction since the correction of astigmatism is a formidable problem of pattern recognition.

Log-log scale roughness spectroscopy of surfaces

1993 ◽  
Vol 51 ◽  
pp. 224-225
Author(s):  
P. Fraundorf ◽  
B. Armbruster
Keyword(s):  
Power Spectrum ◽  
Autocorrelation Function ◽  
Power Spectra ◽  
Scanning Force Microscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Scanning Force ◽  
Lateral Structure ◽  
Scale Roughness

Optical interferometry, confocal light microscopy, stereopair scanning electron microscopy, scanning tunneling microscopy, and scanning force microscopy, can produce topographic images of surfaces on size scales reaching from centimeters to Angstroms. Second moment (height variance) statistics of surface topography can be very helpful in quantifying “visually suggested” differences from one surface to the next. The two most common methods for displaying this information are the Fourier power spectrum and its direct space transform, the autocorrelation function or interferogram. Unfortunately, for a surface exhibiting lateral structure over several orders of magnitude in size, both the power spectrum and the autocorrelation function will find most of the information they contain pressed into the plot’s origin. This suggests that we plot power in units of LOG(frequency)≡-LOG(period), but rather than add this logarithmic constraint as another element of abstraction to the analysis of power spectra, we further recommend a shift in paradigm.

Optical fibres cut their losses

Nature ◽  
2003 ◽  
Author(s):  
Philip Ball
Keyword(s):  
Optical Fibres

Interlaboratory evaluation of theoretical modelling techniques for single-mode optical fibres

1992 ◽  
Vol 139 (5) ◽  
pp. 353 ◽  
Author(s):  
J. Pelayo ◽  
J. Paniello ◽  
N. Gisin ◽  
J.W. Burgmeijer ◽  
M. Blondel ◽  
...  
Keyword(s):  
Single Mode ◽  
Theoretical Modelling ◽  
Optical Fibres ◽  
Modelling Techniques

Test of directional photoionisation models of second harmonic generation in optical fibres

1992 ◽  
Vol 139 (2) ◽  
pp. 133 ◽  
Author(s):  
N.M. Lawandy ◽  
T.J. Driscoll ◽  
C.L. Adler ◽  
N.M. Lawandy
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Optical Fibres
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