Gentec-EO Beamage-3.0 - Manual (Page 37)

Beamage-3.0 User Manual Revision 6.0 36
5.1.2.1. Diameter
The “Major Axis” is the beam maximum width whereas the “Minor Axis” is the minimum beam width.
The “Effective Diameter” is the beam’s diameter considering it is circular.
The effective diamete
r is only valid if the ellipticity is greater than 87%. If the beam’s ellipticity is lower
than 95%, the effective diameter will by greyed-out, indicating it is not valid.
The
“Ellipticity” is the ratio between the minor axis and the major axis. For a perfect round Gaussian
beam, the ellipticity would be equal to 100%.
The
“Orientation” is defined as the “angle between the x-axis […] and that of the principal axis of the
power density distribution which is closer to the x- axis.” 1
. From this definition, the angle is comprised
between -45
o
and 45
o
.
For more information on beam diameter computations as defined by the ISO-11146-1:2005 and ISO-
11146-2:2005 standards, please refer to Annex A ISO11146 and iso11670 Definitions)
Warning
According to the beam definition, the displayed measures will vary. For
example, for a 86% effective diameter, only the effective diameter will be
displayed, as the major, minor axis, and orientation are not relevant in a
perfectly circular beam.
5.1.2.2. Centroid
All positions are relative to the image center which is (0,0). The horizontal axis increases towards the
right-hand side and the vertical axis increases towards the top.
Figure 5-3 Fixed Coordinates System for the Sensor
1
International Organization for Standardization, ISO 11146 :2005 Laser and laser-related equipment –
Test methods for laser beam widths, divergence angles and beam propagation ratios, 2005, Geneva